Should you be aloud to do this? To use someones likeness to create anew?
I mean, if someone opts in post mortem, that's fine. But otherwise.... unless you understand what your "estate" entails, it's pretty crazy.
You're talking about licensing a likeness and it is a licensing process. If the estate of Peter Cushing weren't on board they'd never do it. There isn't a lot of caselaw setting a precedent but there's certainly prior art.