My hardware is a one-off, built by a friend in his basement. He might have made a few, mostly out of curiosity for the process and then he moved on to other things. There are a couple of issues with the bridge, as far as adjustability and stability goes, but it does the job. It's a huge improvement from the stock bridge as you can now feel the strings drive the whole body and the sustain is much improved. The brass nut is just a piece of brass stock from the hardware store, machined into the right shape by one of the wonderful folks at Woodsong's Lutherie, here in Boulder, no big deal. He also built the pickup surrounds, which was a pretty big deal to get to conform with the curvature of the top. I think that was the single most expensive part of the upgrades.
The electronics I installed myself, but I do that with all my basses. It was a little more involved than most, as I had to rebuild the filter sections from scratch, but once I got the cap values right, it was pretty easy. At some point I might try to do it again using audiophool caps and components just for giggles. I can't imagine it would be all that much better, but you know the devil finds works for an idle soldering iron! I would have loved for Alembic to do the work, but at the time I didn't get much of positive response, as they have been really busy just doing their own work. I still do have fantasies of getting them to do an ebony board for it and LEDs would be way cool!
I would never do this kind of stuff with my Series I. I'm a respectable solderer, but they really do it right.