Over the span of 50 years, not so much. As long as his resume is, he is surprisingly not a huge gear head.
Fender mostly only gives P endorsements to dead guys or studio/backing players (Sean Hurley, Pino) Jazz endorsements are a little easier to come by, judging from the likes of Adam Clayton, who's pounced on more endorsements in the last decade than Hamm's probably had in his whole career, or at least close to it.
Currently 8 P bass signature models and 5 jazz signature models. Clayton used to have a P bass signature model before his current J. Anyways, not arguing or anything. I think we probably see more of the j signatures in print and advertised.
Before that Peavey,then Dean made Jeff Berlin" specialty basses. So that's 3 companies making a JB bass.....admittedly over a fairly long period of time.....
Im just starting to follow Will Lee this last year. As far as I know he's been a Sadowsky guy for years and years and uses only a hand full of other basses. What do you mean by Flog a lot of stuff?
I was thinking of him when I was readin the answers. Jayson mewsted did the same in his metallica era.
This topic has been previously covered. If Hamm jumps around and makes a pig of himself for having a few more endorsements than the next pro, good for him. Alain Caron has had a few different amp choices before settling on MB, but has been consistent with FBass. No different than getting sponsorships in racing...
Mark King has a signature Jaydee, a signature Alembic, and a signature Status. He has also had a signature Fender Jazz. IMHO, he wins.
The shocker to me I caught while checking out namm 2015 videos. Both warwick and fender have Adam Clayton signature models at the same time.
Not part of the bass world but Eric Clapton has a signature guitar with both Gibson and Fender, ain't that cool?!