I used to help out a gunsmith, now retired and what we would do in a "odder" / "rarer" gun like this, (although they are becoming more common), hit Shot gun news. This was before the inet. In hard copy there are ads from a couple dozen outfits that stock the pistol and some that have parts. Used to deal, occassionally, with Springfield Sporters. Guess they have gone out of business. SARCO, NJ I think has a web site, but parts are in the SSN ad. Tom Forrest was another with a collection of parts. Gun Parts division of Numrich is out there. No telling what they have. Have to ask. Probably best service and highest prices. There was a man who specialized in parts for Saturday Night Specials ... don't recall his name, but if that was what you needed. Those European makers did turn out some quality guns too.
I think the law requires the importer to stamp his ID on the piece, so unless it is a "bring back" you might start there.
I would guess that Gun List has some similar ads, but we were well into SSN before they got started. Otherwise, there is google. luck