If you had a friend that was a machinist, and you gave him the original and maybe a drawing with dimensions taken with a caliper, or maybe even not, I bet he could crank one of those out on the lathe post-haste. The trouble comes with a broken pin and a piece missing. Then you gotta get a diagram made somehow. Perhaps someone with the intact part would make a drawing with measurements. The drawing does not have to be great art as long as the numbers are right. I have a book from the 80's I think, that has a repro of the original instructions etc. for that pistol. It has a weird recoil buffer inside, consisting of a regular recoil spring, and a cone shaped flat spring rolled up to act as the buffer for recoil. I see that the firing pin has sort of a head on the end that is missing from the broken one.
Your gun is like your nose, it is just wrong for someone else to pick it for you!