Check it out, a RM Robin has popped up on ebay:
Mego Removable Cowl Robin 8 inch action figure - eBay (item 260467301899 end time Aug-31-09 11:45:05 PDT)
Description mentions that the emblem is missing, one of the wrists is taped, and that the belt is a replacement, but the mask must be authentic, right ?!!!
And I didn't think it was possible for a replacement mask to look worse than the one Mego crafted for RMR !!