This should have been green. In principle, it could be really powerful for a specific playstyle. Unfortunately, that playstyle doesn't really exist yet, at least not for anyone who can include the card and cope with its quirks.

TLDR

--This is not a weapon for boss killers or full time fighter. -- If you plan to fight three or more times per turn it is very bad, and lots of characters can fight more than three times when the chips are down. --It is terrible against retaliate, damage reduction, enemies that punish attacking/damaging them, and bad stuff token effects. --It is very efficient for flex-fighters who want to attack only once or twice per turn --Especially if they care about evasion or oversuccess --Unfortunately the two hand slots are a big ask for flexes --And few people who would want this can actually include it

The Good

• Dealing 3 damage in one action is really good, and this can do that once per turn forever
• It can also deal 4 damage over two actions like a normal weapon.
• Against 1-3 health enemies you're killing much more reliably in fewer actions, although also at more risk of triggering fail effects. Compared to Machete or Brand, you get two chances instead of 1 to deal 1 damage in 1 action. If you only need 2 actions you only need to pass your +foot test which should be very high skill. If you need 3 damage in two action you do need to pass the foot test but only one of the two basic attacks, where Brand-likes have to pass 2 out of 2 checks.

The Weird

• As Lockpicks has shown us, combining 2 stats can be really good.
• However, there is more support for stacking +foot +book together than +fist +foot, IMO.
• Also unlike lockpicks, this only uses foot sometimes, and it forces you to make fist+1 checks first.
• Most guardians only have 2 or 3 agility, so the second attack is only +1-2 points better than the first one without further boosting. Guardians also have lots of other ways to boost attacks with XP. Making a +1 to hit weapon Reliable or Enchanted for instance might help you more.
• If your agility is 4+, then the gap between your first and second skill checks becomes a problem. On standard the distance between "uncomfortably risky" and "all-but-guaranteed" tends to be about 2 skill points. A 5/4 investigators swings this at 6/9/6, but either the 6s are very risky or the 9 is overkill.
• The whole point of doing all your killing in your first action is to spend your time doing something else useful. But this takes up both of your hands, which greatly limits your options.
• So the ideal user for these would be a high-agility flex character who can get clues with their hands full.

Synergies and Possibilities.

Part 1 -- Should Have Been Green

• Lots of rogues reach 7 or 8 natively with the 2-damage swing, which is better than their other level 2 weapons
• Triggers lucky cigarettes easily
• You could use Hidden Pocket to carry a Lockpicks or Thieves Kit alongside
• with Dirty Fighting you can evade, get +2 to the weaker first swing and then follow up with the +agility second swing for huge skill tests and action compression.
• Evade also turns off retaliate
• Sadly, Winifred/Kymani/Finn can't access this and Skids is still really bad.

Part 2 -- Other clue options

If you can't scam hand slots for an investigate tool, you could rely on snapping up clues from events/allies/skill cards or investigating with spells. That would make you some kind of weird tri-stat build by maybe it's doable if you stack multi-boosters like Crystalline Elder Sign, Dark Horse, Geas, or Composures.

Part 3 -- As a sidearm

You could of course plan to use these just for one 3-damage action per turn and then to follow up with other attack forms. You could soften groups with Mk 1 Grenades and then split attacks to finish multiple wounded enemies, supplement with a spell, or get Bandolier, Boxing Gloves and some martial arts moves. With off-class access you could fold in other once-per-round shenanigans like Chuck-boosted actions, Hatchet throws, and the like.

Part 4 -- The secret super-synergy

The card that actually breaks this wide open is, obviously, Sled Dog. With even 2 dogs down you get two chances per turn to deal 2 damage in one action, at +2 and +AGI respectively, and if you proc retaliate you can throw the dogs under the bus. If you can reach 3 dogs you now have 3 damage twice per round, or the ability to zoom across the map to deliver your 3-damage flurry. If only Leo Anderson's agility weren't 1.

Note: this card does NOT exhaust after you fail a parley and it attacks you. So it will attack multiple times if you fail multiple parleys in the same round.

As per the FAQ, "Enemies only exhaust after attacking if they perform an attack during step 3.3 of the enemy phase. Unless otherwise noted, all other enemy attacks do not cause that enemy to exhaust".

You can look at this card in three ways: as a resource-for-cost engine, as a mass curse generator, and as a precision curse generator.

As a pure resource generator, it feels awkwardly positioned. Rogues have lots and lots of level 0 cash options and if you don't actually want the curses there are much safer and easier ways to get a reasonable amount of setup down. If you play the charm and then activate it twice, you sink in 1 card, 3 actions, an item slot, and 6 curses to generate 7 resources. You can also get 7 resources in 3 actions with Bank Job + click or Faustian +2 click. Emergency Cache/"Watch this!"/Sneak By etc. also generate comparable value. And if you need fewer resources those are all better. So, in green, Scrimshaw only really shines if you intend to click for 12 resources or more. I think most level 0 decks struggle to make meaningful use of that cash or recover from sinking in that many actions. If you have Well Connected you're taking 3 curses for roughly +1 to 1 test each round going forward. With events like Small Favor or Intel report you're spending 2 actions and 3 curses to get 2 clues or damage. That's okay I guess but it's no Stirring Up Trouble, and building all your resource gen into one card risks bricking you if it doesn't appear, although at least items are easy to find these days.

It is more plausible an option for the off-class investigators with Cursed access. Even setting aside synergy considerations, they're mostly blue and purple characters with fewer native econ tools and more expensive level 0 toys. It does also plausibly seem worth swapping in with Adaptable later on if you're having trouble powering up The Black Fan.

On the other hand, this is the fastest and most reliable curse generator available at level 0. Justify the Means and Stirring Up Trouble are faster but one-shot and you may want to hold them for impact. If you actively want to flood the bag, this is a great way to do that while paying for the curse-matters assets you want to leverage with it. It is however a bit painful for most mystics to give up the accessory slot, and you may actually flood the bag so much that you stop being able to get resources from it. Still, this has obvious appeal to folks like Kohaku and especially Occult Reliquary Dexter who can milk it for resources and then swap it for a different accessory or hand item.

Kohaku, of course, also cares about the exact ratio of curses to blessing in the bag, as does anyone running Key of Solomon. Although, since the Key turns curses into resources, the benefit is arguably redundant, so I doubt other characters run both. But, Kohaku may appreciate having this on hand to force curse pulls off his book or to to turn blessings into money by spending an action on this and then buying it back with his passive.

I don't know if this card is good or not, yet that's not the point. This is one of the most thematic cards in the whole game. I can only imagine Alessandra Zorzi saying, 'So you don't like my words? Maybe you will like my lead.'

Vincent Lee has a dark secret, he does not want to talk about. You know, how caring he is about any wounded bystander, he encounters? His mind suffers deeply, whenever he can't help, or at the very least keep them alive. This was not always the case. Once he visited Dunwich, and let somebody die, without regret. He blamed the Unhallowed Country for that.