The question is what were the guns made from. If someone knows...and knowing would require either a copy of the part drawing with material specification or you worked at the original maker and have personnel knowledge...please tell us the material?
If you are right handed and you shoot left handed then the issue of losing a digit doesn't have the impact, however I do not and therefore I would leave it alone. grin
What guarantee do the various folks doing the hardening provide? And what disclaimers?