Flip over that R65c and check for tiny blue threads (there might only be one, so check carefully under high magnification). If so, that's an R65d. That stamp has the right shade of green and a late-date handstamp that indicate it could possibly be a silk paper.
Regular R65c: $12.00
Silk paper R65d: $110.00
Silk papers are always worth checking for. Cancel dates of 1870 and later are a good indicator of stamps to check. I've cherrypicked countless examples out of dealer inventories... speaking of which, my annual show season starts a week from Friday at Indypex. Woohoo!
