Check eBay. There are plenty. I will state the obvious, but it's a helpful obvious: 1) Any spec of dust will be super-visible. Trying to clean dust off once y

Check eBay. There are plenty. I will state the obvious, but it's a helpful obvious: 1) Any spec of dust will be super-visible. Trying to clean dust off once you're done is painful; you'll usually just make more of a mess each time. It's a lot easier to do it right the first time. Go really overboard here. Wash your hands AND use gloves of some type without lint AND use tweazers. Make sure the environment is impeccably clean. Vacuum, dust, etc. the room. Wash the table. If you've got a HEPA air filter (and with COVID + pollution, it's not a bad idea), move it into the room. Go wild. 2) Use a dSLR you don't care about. If you're who you sound like you are (an old-time photography nerd), you probably have a 15-year-old one you never use which sells for $100 on eBay. Use that one. I did this with my favorite dSLR, which was from 15 years ago. It's obsolete, but the controls fit me like a glove. When I finished, the metering was messed up -- it consistently over- or under-exposes in auto. I don't know if I broke something, or perhaps if it just failed at some point before I started (it'd been sitting in a drawer for maybe a decade now; I didn't test it much beforehand). I didn't break anything (else?), but it would have been really easy to do so. These are fine, precision, delicate parts. Don't use a $2000 modern model. I use it as a full manual camera now, and it's a heck of a lot of fun.