Jaw screw is stuck. Need guidance

[excess650]

Heat is what I will be doing.

The weapon is an early 18th century piece, but was restored a good bit

The lock appears late 18th century.

 

[Relic shooter]

Will the acetone ruin the patina?

Acetone hasn't harmed the patina on my originals, as others have noted it just softens the crud & makes it easier to remove.

 

[toot]

Old gunsmith trick, soak the screw in Coca-Cola for several days. It should break free.

roger that, COCA COLA, will free up anything!!

 

[excess650]

roger that, COCA COLA, will free up anything!!

Pabst Blue Ribbon

 

[foxm1754]

Another "old trick" would be to place some small pieces of beeswax around the perimeter where the screw meets the hammer. Gentley apply heat until the wax melts and turns to liquid. When doing this try to apply heat so molten wax will "run" into joint ( just like soldering). Have used a soldering iron to achieve this effect. If heated no further than wax melting, temper of other parts and finish should be preserved. Goal is to have beeswax drawn into fastener threads and make removal possible, after wax cools.
From original photo may want to carefully "square up" the standard screw slot before attempting another removal also.
You can do it....you've got this...

 

[Robin Henderson]

https://mymadeintheusa.com/usa-made/gunsmith-screwdriver-set-with-ratchet/
This little tool will works great with the proper screw head. Do your soaking and carefully apply pressure with this. The Chapman ratchet tool, that is.

 

[stewart.leach]

I'm looking at that very buggered hammer screw versus a fairly virginal top jaw screw and wondering if the jaw screw was replaced with something with the wrong thread. If so, go gently, you might be able to restore the original threading.

As noted above, patience is the most important thing to apply to stuck screws. Repeatedly soak in penetrant and heat. Give it a couple of weeks!

 

[TheTyler7011]

I'm looking at that very buggered hammer screw versus a fairly virginal top jaw screw and wondering if the jaw screw was replaced with something with the wrong thread. If so, go gently, you might be able to restore the original threading.

As noted above, patience is the most important thing to apply to stuck screws. Repeatedly soak in penetrant and heat. Give it a couple of weeks!

Yeah definitely been messed with. Appreciate the feedback. Taking this slow