Time no longer gives the ability to do this with motorcycles but about a year ago I started doing this with guitars donated to the Salvation Army thrift store. I repair, restring if necessary and polish and research them as to age and value. Much like wrenching bikes I get to try out a lot of things I wouldn't buy, learning along the way. Just finished number 25 which is not only a milestone but a unique guitar. A two neck electric with a six string on the bottom and a twelve string on the top. Metallic candy red and black. Very cool and very heavy! I do this on a volunteer basis although they give an unasked for store discount and if I'm looking for something in particular the manager sets it aside. If it's a guitar for my kids (5 have guitars, 2 have ukelele's) the're free. Keeps me busy and saves many from the dumpster, plus they get way more money for them and someone gets to play them. CHEERS.