My first project was rehabilitating my Technics SL-23 turntable. I was really dismayed a few years ago when I fired it up for the first time in many years and discovered it would no longer maintain a constant rotational speed. I thought it was junk. Thanks to the internet, and sites like this one, I discovered that they could be fixed.
Inspired, next came my Marantz 2226 receiver. This proved to be less work than the turntable but more satisfying.
Right now, I'm restoring a pair of BIC Venturi Formula 1's that I've owned forever. Don't laugh, I know they're not TOTL but I've owned them as long as I've owned the TT and receiver and figured they would be a good learning experience. I'm having the woofers reconed while I replace the cheesy vinyl woodgrain veneer with real walnut veneer (I like woodworking, too)
I'm afraid I've caught the bug - I've always loved restoring old stuff but had not discovered old audio stuff until now. My avatar is a car I bought in 1974 and recently restored...