You did well at $150..pretty much standard for a used Rossi .22 in good functional condition.
Rossi made the model 62 from 1970 to at least 1999. There are 3 basic derivations of the Rossi 62, all types (SAC, Magnum, SAR) should be clearly marked on the barrel:
Rossi 62 Gallery SAC Carbine. Blued or Nickel finish in .22 LR only. 16.25-inch barrel, 10-shot tubular magazine. 1975-1999
Rossi 62 Gallery Magnum. Blued finish, or RARE in nickel in .22WMR, 23-inch barrel & 10-shot tubular magazine. 1975-1999
Rossi 62 Slide-Action Repeater. Blued or Nickel finish, Calibers in .22short-Long-LR, and also in .22WMR Tubular mag holds 13LR, 16 Long, or 20 Short. 23-inch barrel, 39.25-inches overall. Weight 5.75 lbs. Imported 1970-1999
Interarms closed it's doors in 1999, so there isn't any help from that angle. BUT, since it's a Rossi...you should be able to download the manual soon...Rossi's site isn't complete yet, but they are supposed to be working on a Manuals page.
Parts are available at Numrich.com
Hope that helps youse guys