Can't say about this particular film, but I've read that 70mm blow-up prints often do have slightly more detail than 35mm prints. Not sure how the math behind this observation pencils out, but maybe it's just that size matters more than you'd think. Frankly in this case, though, I'd say practical matters such as how well the film was cared for, how long it was in circulation, etc is far more of a concern than hypothetical best-case scenarios.
EDIT: Beat to the answer by happycube.