If that's a real WZ frame (WZ stamped on the BB) it belongs on a WZ-507 restoration
WZ frame probably worth $250
The Schwinn WZ-507 was a heavy duty bicycle made for the Whizzer engine kit.
Not a Factory Production Whizzer.
Get a Schwinn frame from the 70s and 80s $100 it will be just as good for your Minerelli build