Cave with very strange rotating ring/saddle set up.
6". I would jump if it was local.
I want to see down the tube. The spider may been replaced with some large diameter bolts or all thread. The primary has also been moved way up the tube so I expect non-original optics. Looks like bit of a kludge to me. Still not a bad deal for the mount.
Edited by WoodyEnd, 06 December 2017 - 06:49 PM.