Right after posting, I saw the last post rec "Goof Off" -- I own some of that, went in the shop to try it --- NOPE!!!
Didn't touch this sticky substance... all the usual things I use for sticky adhesives are not doing anything to this sticky mess.
I have exactly the same scope. After reading this forum I thought I will throw everything on the scope. The winning solution is Napier gun cleaner and lubricant. I covered the sticky surface with the spray, waited 10 secons and scaped the gooey stuff off with wooden barbeque sticks with the flat wide end bit which is a bit sharp. Underneath is the painted metal tubing. I also used some kitchen sponges with the white (not green) scratchy pads, finally some cloth on the sticks again vigorously rubbing. I finished up with iso-propranolol. I used the same method to the ocular holder bit and the mount, which were also sticky. Final finish to all WD40. Now it looks like new. The painted tubing is perfect and the Celestron Ultima 80ED logo did not come off. I hope this helps.