Keeping old gear is a waste of bench space for most shops and the math backs that up. You said yourself you barely touch a soldering iron now, so why would you keep a scope and a tube tester taking up room for three radios a year? Selling it off lets you put that money into gear you actually use every day, and the vintage guys who really want it will just buy their own testers on eBay for cheap. Cleveland shop can do what he wants but he is running a hobby, not a business, and hobbies do not pay rent. If the vintage work dried up tomorrow he would be stuck with dead weight he cannot even give away.

Sealed bearings still get grit in them and that 2019 Trek probably saw some wet rides. I do mine every season on my own bikes, takes 20 minutes and saves the hub. Tell the Amarillo guy he owes you a set of bearings.

Honestly the first thing I'd do is get that coin authenticated before anything else, because there are a ton of fakes out there and even real denarii from that era usually show up in Europe or the Middle East, not Ohio. If it's the real deal, my question is where exactly on your property did you find it and how deep was it? Was it just a few inches down in topsoil or was it sitting in a layer of clay or gravel that looked undisturbed? That detail matters a lot because it tells you if someone dropped it recently or if it's been sitting there for a long time.