Parts can be tough to come by, but they generally are available. Try Gun Parts Corporation.
Ammo is another matter. It can be virtually impossible to find shooting quantities of .35 WSLR. It didn't last very long, as it was seen as too expensive and too under powered for just about anything.
Ammo was produced up through the 1930s, but was, I think, dropped in the run up to World War II and not restarted.