How hard would I have to hunt to get the right BD(s) of Superman 2 and Superman 2 RDC, to have the necessary footage?
What do you mean by the “right” BDs? Are there different BD releases of 2? I picked up the UK anthology set years ago simply because it was cheap.
EDIT: I’m pretty sure that the DC in the anthology set doesn’t differ from the first release (if that’s what you mean).