I have a Celestron C8 in very good condition with very good to excellent optics. (Saturn is wonderful when the seeing is good.) It has Bob's knobs, a beautifully flocked interior, including the baffle tube, (which really increases contrast on deep sky objects). It has a removable hardwood mounting rail (easily customized for your mount).
The optical coatings are in excellent condition. The only downside is some irregular paint where a small (4mm deep) dent was repaired, which of course does not affect the optics in any way. Comes with 1.25 visual back, and 1.25 prism diagonal ad 6x30 finder. $400 shipped in continental USA or best reasonable offer. Thanks for looking, Bob. (Please note that the picture was taken with a flash bulb, which is why the nornally invisible flock paper is visible