First off, anyone know where to get magazines from? And will the CZ 82/83 magazines work with this gun?
Yes CZ83 mags will work, but they will extend out of the mag well, as they are longer by about 1/2"
Where to get parts?
You can get parts directly from Sphinx. Do a google search for Manuel Wipf. He is the gentleman that handles orders by email. He deals in cash only, so the search is to confirm that this is on the "up and up". Though he is Swiss, he accepts dollars.
If you have a manual, ask Manuel for new parts. If you have no manual then go here to get the parts numbers.
Though it has been a few years, I have dealt with Mr. Wipf personally, and he delivered parts quickly, considering the overseas travel time. Good luck.