Good call on the vinegar and clear coat—I've done something similar with old fixtures, and it's surprising how well they hold up. One thing I'd add is to double-check the threads if you're planning to screw pieces together. Sometimes corrosion can mess up the threading, and you might need to chase them with a tap or die set. But yeah, totally agree, seeing something old and rusty turn into something useful again is pretty satisfying...especially when it actually lasts.
I've gotta be honest, vinegar and clear coat might work for fixtures, but I'd be cautious about old pipes. Fixtures are one thing, but pipes deal with constant pressure and water flow—if corrosion has weakened them internally, no amount of surface treatment will fix that. Learned this the hard way when I tried salvaging some old plumbing in my first place...ended up with leaks everywhere. Sometimes it's better to bite the bullet and replace rather than risk water damage down the line.
