I have a Kramer Ferrington acoustic bass that was supposedly built for Nikki Sixx. It has a headstock similar to that of a Fender, as opposed to the pointy ones that were standard on the Ferrington. He had given it to an engineer that had designed an old home studio of his, and that guy sold it to me. I see Nikki at the Starbucks in Malibu all the time, and I keep forgetting to ask him about it.
I also have a Carvin bass that I bought off of Clay Anthony, who was the bass player of the LA band JUNKYARD. He sold it to me dirt cheap for some heroin money just before he left/was kicked out of the band.
I stopped using that bass years ago, and it was just sitting in my garage in a case when I did a job with Harry Shearer. I took the bass down to the studio one day, and Harry signed it for me as Derek Smalls, from Spinal Tap. I still need to get a museum case for it to put up in my studio next to...
My Les Paul, autographed by Les Paul. (Okay, Les Paul never OWNED it, but it's still a cool story.)
On my way to a party that Les Paul was going to be at, I stopped at GC and told the sales guy that I needed a white Les Paul. He asked why it had to be white, and I said, "Because I have a black pen!"
The guitar has never been played, and is in my control room, in a museum case along with the black pen, and 2 pics of Les, the guitar, and me.