Hi C.W.,
Thanks for your input on the drive washers. My 494 Rotating Beacon with the 3-fingered washer has been reliable since 1957 although granted it is only run at Christmas time.
It's entirely possible that the Radar tower with its 3-fingered washer will be just fine once I stabilize the antenna pin/magnet hole issue. I'll take it a step at a time.
Roger