Thank you for the advice. I've worked on (meaning, designed, built, updated, repaired, adjusted, aligned, re-coated, star tested, rewired, and automated) telescopes between 4 inches and...well, 8.4 meters across.
I've built domes and poured piers for professional scopes, I've folded myself into a pretzel to squeeze into the fork arm of a 2-meter class telescope to measure pre-load on the right ascension gear, I've stood on the primary mirror of the Large Binocular Mirror telescope (but only one of the two...), I've hand glued metal disks on a thin "contact lens" mirror so that pizo-electric actuators have something to grab on to when they warp the mirror for adaptive optics, and I've put an evaporated aluminum coating on an experimental carbon fiber mirror. I've run wiring up the side of a mountain, I've dug ditches at 11,000 ft elevation for new fiber lines, I've even run an end-loader to clean the road of snow during the winter, so the next group of astronomers can get to the scope.
About the only thing I've not done is cut a brand new worm gear on a mill, I'll leave stuff like that to someone with more experience.
That being said, it was almost always as a team. Jumping in alone, even for something small and relatively simple like a commercial telescope, is scary. And yes, I have broken glass before, I have a piece of a $50k mirror hung on my wall at work to remind me that Big Science means Big Mistakes.