I know someone that has a set of Griffen & Howe rings and mount for the M82. It has the 3 mil serial number stamped into the side as it should if it was actually used on an M1C sniper. I believe he was asking $900...or maybe 1K.
Jeremy, Truthfully both the scopes (not so often) and the mounts/bases show up on either ebay or Gunbroker on a pretty regular basis. I sold a base a month or so ago, ($400) figure $2 to $3,000 for a correct USMC manked Kohlmorgan, which will need T4 Stith rings (26mm). All of which is pretty pricey for something you are putting together. An M82 or 84 setup will still probably be $1k by the time you are done, an M81 slightly more. You can also be on the watch for an early Lyman 4x which the M81 / M82 scopes developed from. Have patience, Skid