Not only did your ECU come from a '97 Supra, but it ran from May 93 to Sept 97, and according to the EPC, it lists for a 'JZA80 4FC TWC'.
Now IIRC, the loom you have is a Nov 93 to Aug 94 and is also for a 'JZA80 4FC TWC'. So, that 'model' loom did have that 'model' ECU plugged into it during its time on the production line.