Am I just looking at reflected sky, or are those tube rings blue? If they are blue, can you tell me where you bought it? I painted my tube rings blue about a year before I sold my RV-6 in 1975.
I thought they were slightly darker blue, though. And my mount didn't have a lever on the side, just a big bolt with a socket head (I think). Of course that could be a later addition.
(Addendum: I'm not sure if I painted mine blue or just seriously considered it. The color would have been Ford engine enamel, which is what was available to me at the time.)
Just polished top halves. Must be the sky.