Well, still not sure of the manufacturer.
Some of the Pietta screw set screw will fit, some will not.
I also found out that the cylinder that was with the gun is likely not the one that came with it.
After spending 2 hours reducing the Pieta hand to actually fit (pivot shaft too big, hand too long and too wide) and replacing other parts,
When I mounted the cylinder and put the wedge in, it all bound up between the cylinder and the barrel and frame.
So - back to properly fitting the cylinder. Another hour and a half of filing and fitting.
FINALLY got it all back together - only to discover the bolt\trigger spring did not reach the trigger shelf.
I did some heating, bending re-hardening, tempering and now have that taken care of.
I did order a new spring and just in case - a new trigger.
Another week delay of course will now happen.
Everything is functioning correctly now.
The new new set of nipples, the .375 ball mold are on the way.
I will admit that the gun was a real basket case, but I also got a great deal of satisfaction in going through it and saving it.
It's old and still mostly a mystery on it's origin.
The only part that I know is Pieta is the cylinder - which I also know is not original.