Hi Don
It's interesting to read your very methodical and engineering approach to the problem of vibration in long lenses.
Mine is more Heath Robinson, my longest lens is the AFS 300 f4, which I use in conjunction with the TC 1.7. The lens collar on that lens is useless, so much so that I almost gave up on it, just could not get a sharp image due to vibration.
I bought a Manfrotto 501head and the images improved somewhat but were still a bit fluffy.
I read one thread on the net, where the responder had lodged a canister from an asthma inhaler between the collar foot and the lens barrel and had found a marked improvement in the quality of his images.
I improvised using a plastic cork from a wine bottle, around which I super glued a covering of 3mm thick rubber sheet, cut to size, and with that lodged in the gap between the barrel and foot plus the 501 have been very happy with the results.
Best of luck with your lens.
Brian
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