Swivels are about $175 from Boxy and there is a single one for sale in the yard sale right now. Assuming no real electronic design is needed, just machining parts, basic soldering and hacking 2 A61s, I think people would gladly pay $4-500 for a pair of cables. Also, there's a chance that the parts needed from the A61 could be ordered individually if a service document ever turns up.
Again, my offer stands to chip in on a single A61 to use for parts for a prototype cable. Maybe Richard would consider incorporating a hacked A61 into his design so the capsule doesn't have to be hardwired?