Nothing under the Lever? Show a pic of the other side. As far as I know, Pietta never made the small frames. The ones I do know about are ASM, Uberti, Palmetto, and possibly DGG. Perina Ruchetta made the small frames in brass.
The larger one is "Mid-Century Modern";) The Hex Nut and electric arc welds give it away. The other may be old, or it may be about the same date as the other. .450 is possibly used in a revolver. The .350 ball would be a decent fit for a .38 cal rifle.
They are screw barrels. Find the right size ball, fill the powder chamber(it won't hold to much), put the ball on the seat, screw the barrel on, prime and fire. I'd use 2F just because the pressure would be a tad lower (velocity down too).
Looking at your pics. The barrel needs to be set back a bit so the drum is centered on the lockplate. Before ANY fiddiling with the nosecap. Then if necessary the nosecap can be fitted.
Make sure to use a VERY HEAVY backing anvil. A trailer hitch ball still on the truck works quite well. You don't want the plate to have ANY flex at the stamp point. Be prepared to have to slightly straighten the plate afterwards, as the stamp may cause it to warp.
As someone who has run a lathe a time or two.😉 Those look like the chips from the threading for the breech plug. The barrel was probably single point threaded, and the operator didn't clear the bore. 🤬
Not silver solder, or at least not high temp silver. Clean the tenon, flux and tin it, and reinstall it. It wont take a lot of heat to do. Otherwise it's a British made gun, can't tell much more than that. BTW nice gun.
What I read is that the statute of limitations for the theft has expired. Therefor the only thing they could prosecute on would be possession of stolen property. Then the prosecution has to prove he knew the arms were stolen. This way he is at least convicted of something. Also the probation...
Navy here. The purpose of a "Dog Watch" is to cause a rotation in the watchstanders. The typical watch rotation is 4 hours on and 8 hours off. So standing a half watch means you do 2 on and 6 off. After that you're back to 4 and 8, for a week.
That's common lead free flux core plumbing solder. Flow temp will be around 400-500 F. The flux number is the type (acid, rosin, whatever) The 3.3% is the amount of flux in the core. Silver solder for parts has a much higher silver content, all the way up to pure Ag.