Union 1 25 acp pistol brought back from WWiI

[jsmi1251]

I am looking for any information, along with parts for a pistol my great-grandfather brought back from WWII. It is a "Union 1" 6.35mm (25acp). From what I've found is that it's copy of a Baby Browning or FN 1906; made either in France or Spain. The frame & slide are fine, barrel is on hand, though it is not in good shape. The hammer will dry fire. Firing pin is stuck protruding. I would like to get it in working condition if anyone could help me out.

Pictures are available if they should help.

Thanks to all in advance!