Never seen one of those - it's pretty cool, I'd use it on a custom build in a minute (raw brass!!!) on a very light-weight bass!

) Are they still available somewhere? The debate about non-reversible mods is really something that is cringed at more with passing time. (as you know) Think about the famous players who have modded their basses to make them theirs; Billy Sheen, Mike Watt,
Jaco... to name only a few. Then there was the late '60s-'70s player-driven trend of stripping finishes to natural. I did it also to my cherry red '68 EB3. Back then (early '70s) I didn't know anything about the finish effecting tone - I just liked the way it looked/felt natural. There are DIY 'hack jobs' and that is always sad to see - but the whole vintage/stock/'unmolested' thing was just a lot less something players thought about then.