Does it seem to anyone else that the standing buffalo now is a little larger than it used to be? Maybe the helmets are larger than they used to be in the 60s and the buffalo was enlarged to compensate.
Looking at the hype video the Bills released about the standing buffalo, it seems like the 1960s helmets had smaller buffaloes. There's a clip in it of Cookie running, about 80% of the way through the video, and the buffalo looks smaller than it did on Joe Ferguson's helmet. Maybe the Bills made the buffalo larger during the OJ years.