Aha, a revival of a very old thread. I had the Moses graphite bridge on my Juzek for about three years, still have it. I found it added some brightness and perhaps a little immediacy to the sound, but it wasn't really something I needed from the instrument, and off it came. I suspect it would be something that could benefit a darker sounding instrument, and as we know, there are many ingredients that can affect a bass, but you never know which way until you try it.
One disadvantage is that, with no wing, it will rule out some pickups. Also, I tried the K&K Double Big Twin on it, that's the pickup that has transducers you stick to the top of the bridge. Unlike wood, which necessarily warms up the sound, the graphite was cold and the sound harsh. However, it would be interesting to hear a Full Circle in it.
I would think that the board you ran across was also a Moses-- you are correct. They were available with a piece of veneer on the back. He determined that the best mounting method was epoxy, as hide glue wasn't compatible, so the veneer was epoxied to present us with a hide glue friendly surface.
I haven't really dealt with Stephen for quite some time, though I've yakked with him periodically at NAMM in Anaheim. The graphite boards never really took off, and I'd heard of issues with them a few years ago, so I never revisited them.