Rich, it is kind of my lucky day. Thanks for the Marstar tip.
When I went to dissasemble one of them, I discovered that the front plate and the little button are missing. The screw-on barrel nut is there and held with a home-made button. Luckily, I have another pistol so I can tell what is not right or missing.
Who would carry parts for the Frommer-Stop?
Regards, Ned