To answer your question. There is no Federal Manufacture Codes.Is there a site to look up the Federal manufacturer codes used to register handguns? Sometimes, the local authorities seem to take forever to find the correct code when uncommon pistols and revolvers are presented.
I do not think that is the problem.You can also post the written informaiton that is on the gun here and we may be able to help you ID it. A photo will also help in IDing the gun.