Paul,
On the Solido Sherman tanks I own (15 to 20 years old) the metal tracks used to oxidize and would have a coating of dusty white powder look to them. I took them all off cleaned them with a soft wire brush, spray painted them with Rustoleum. Never had a problem again. If the new version has plastic tracks may not be a bad thing. Even if the tracks are plastic I would repaint them. Silver tracks do not go on a Sherman. Again I think the MTH product is fine with the tanks they used.
JohnB