That's a nice Parts-o-caster you've got there, Walter, very unique! And congrats that it turned out so well. You must have done a few things right there. Interesting pickups, too. I've never seen one of those.
A test like Ralf suggested would have to be done in the same guitar and even then I would expect other vintage Franz to possibly sound different, and probably the new ones, too, although to a lesser degree. I don't think one can generalize here. Some things just cannot be registered universally. But Walter may have a fun day (and a lot of soldering work).