I think I've avoided it out of principle, and stuck to the version with the original musicians before Sharon et al. tried to screw 'em over in that particular way.
There's the RickToone tremolo, which has an individual cam per string so everything stays in tune, but it looks like it's only available for volume licensing and not as an after-market parts purchase. I don't think it can do all the fancy stuff this one does, just the relative pitch preservation.
To me it looks like they just made PCBs that are basically eyelet boards but with pads instead of actual eyelets, and then hand-wired everything from there. Hence how they were able to have that little patch of traditional looking PCB for the op-amp. The rest of the board just doesn't have the...