Zinc rot on Spectrum Murphy Roof Boxcar car diecast trucks

[Chris9017]

I'm sure I'm not the only one who's had problems with zinc happen on the 1:20.3 Scale Spectrum Diecast Trucks on the Murphy Roof Boxcars.  All 3 of mine have had their trucks come down with zinc rot.  I was able to buy replacement ones for one, and get one replacement truck for another, but they're now out of stock and I can't buy anymore.
Do ones from Accucraft or Ozark Miniatures work? 
Also do you think Bachmann will produce a new batch given that they're ALWAYS producing batches of metal diecast trucks for the Spectrum Shays?
Any answer will help, thank you!