IC should be M2764A from ST, however marking is fake. Speed grade and date code cannot be trusted. Most likely pull from old equipment sold as new IC. In the past I once made 2 orders of the same EPROM from the same seller with 1 week difference. First batch was fine, second batch was very old 21V EPROM from AMD instead of 12.5V from ST as I figured out by look of silicon die. And markings were exactly the same, including date code, on all of the EPROMs, despite them bearing different dies.