Okay, I like to tinker and buy other peoples broken stuff.
My 2 projects are a russian bino and a atn mum14
The russian bino is a gen 2, but the battery cap corroded and the PO used pliers to try to open it. They ripped the threaded section out of it. I have repaired it, by soldering a thin brass sleave on the brass battery thread section and epoxied it in to the battery tube. This gave it better support than the cast reinforced plastic that cracked. I also tried to get a 10130 tube running in it, I did but it wont focus correctly. At least the russian tube is extremely clean and high res amazingly. It will be a nice little cheap dust collector, that works.
Other project, I bought a atn mum14 with a bad board. The seller said he tried to direct wire the tube to the switch and just did a bad soldering job and it would not shut off. Well he was right on the bad soldering job, but he thought the switch was a maintained switch and it is momentary so you would need to hold the switch to turn it on and use it. I have reached out to the russian maker of the housing to get a board. I have not heard anything back yet. So I may be making a replacement board that will work the same as the factory board, press on, press off. It will have mosfets, transistors and such, and will work like factory when I am done. It wont have the IR light or bright light shut off, but I dont care. I paid so little for the housing I could sell the optics and make a profit. The only thing that is upsetting is after I did a diagnosis I messaged the seller to let him know he was wrong on what he did, he has not responded in any way, even I am sorry I was wrong. In his post he said it just needed the soldering job corrected, well he was wrong.
Two things from this post, even it is broke it maybe be fun to fix, and watch out for others broken stuff it may drive you nuts.