Anyone have any knowledge of if or when the 39 9N loop rims were zinc plated? Earliest photos of the early 39's at the world's Fair in New York in 1939 show only painted rims. I have not seen later photos of the loop rim tractors having zinc plated rims although I have seen a shot of one having 28-inch loops that were plated. So am wondering if they ever came zinc plated for the 32-inch rims. Not sure how long the 32-inch loops were equipped on the early 39 tractors.