Another thing with alloy bases is sandy soil actually erodes them from within. I used to notice the inside of the late 70s Mustang my dad used for odd mowing jobs would always have a clean silver finish from all the sand blasting going on inside. Even then, I was concerned about this on the soft metal and thought a steel deck would be better suited to those conditions.
My fears were confirmed when I saw as online picture of an alloy base hi arch Victa from the same era where years of this sand blasting effect had made long thin openings all along the base like a knife.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!