The question is, how expensive would
it be to restore the Trams for railway usage? And we're not even getting into the red tape related to crash safety.
The bureaucracy is going to want something that can T-bone a car safely at a level crossing going design speed, guys. I'm not sure you'll ever get that with a W without completely rebuilding it (by which point, you may's well invest in a new railcar anyway).
Sorry if I sound a bit pessimistic, but as neat as it would be to see the Trams run on heavy rail in revenue service, you'll never get the crash safety required, and I can foresee the Dieselization expenses (as well as the $$$ required rebuilding the Trams for safe 80km/h running once more) simply being prohibitive. You'd be better off buying some clapped out Diesels from Adelaide when they'll inevitably be sold for dirt cheap, or just simply buying more VLos.
I know I sound a bit foamy and pessimistic myself, but I simply see zero real good chance of seeing restored Z's and W's Dieselized and running on the heavy rail network inside Bendigo. They belong on the Tramway, not the Railway.