OK, I mistook your Roth-Sauer for a short 1905 Mannlicher. Your 1905 Mannlicher is in really great shape. It looks a lot better than mine and mine's in better than "good" shape.
That guy on gunbroker is at $67 for only 10 rounds, and all have stiff primers. I've been told 30 super carry is extremely close to 7.65x21 and can be converted to 1905 Mannlicher, I just need to find someone who reloads to do that for me, and let him test fire it first. Found this on reddit:
"7.63x21mm uses the same .308, 85gr bullet, but is in a shorter, straight-walled case. You can use otherwise unmodified .30 Super Carry brass and run it through .308 pistol dies (.30 Luger, 7.63 Mauser, 7.65 TOK, etc.) with a 7.65 French shell holder. I also have CH4D 7.65 Mann dies, and they don't really work any better, tbh. Cheaper and easier just to buy Lee 7.65 MAS and .30 Luger dies and not wait a year. I use the PPU .3065 TOK bullets with 2.4gr of WIN 231. Runs good in both of my 1905s."
Also found this online: "Yes you can use the [30 super carry] brass. I've been loading the Sierra 85 grain 0.308 diameter round nose soft point."