They are nice little pistols that are just now becoming collectable. Yours is a older model as it is Bohmische marked. Soak that gun in some oil, then use a dental scaler at a light angle to scale the active rust off. Go light and you will not damage the finish as it is rust blued. Here is what one looks like in better condition, from my collection.
Thanks a ton. What kind of oil would be best to soak it in? And do I submerge it or just coat it, and let it sit for a while. The gun is in pretty bad shape, I took it apart and it is completely caked, solid black on the inside. I plan on taking some good time this weekend after my USPSA match and putting some TLC in it. Do you shoot yours regularly? I think it'd be pretty awesome shooting a gun that was shot back then, kind of like being a part of history, same feeling with my Nagants.
Just use some good penetrating oil like Kroil. I do not shoot mine as the grips are made of a material that get very brittle with age. Original grips can sell for up to $100.
I have one from the same era, the ones marked bomische waffenfabrik were made in the period between the annexation of the Sudetenland and the beginning of WWII. after the war began all were roll marked FHN as the factory code.