IIRC the GOOL code was compiled by a compiler written in Common Lisp. If that compiler code survived, it's probable that it would still work today with minimum

IIRC the GOOL code was compiled by a compiler written in Common Lisp. If that compiler code survived, it's probable that it would still work today with minimum / perhaps zero modifications. (No idea what non-standard CL features it might have used.) Of course the output wouldn't be useful for anything but a PS1, but you could change that, and never have to touch the GOOL itself as you say.