They did do dual air U-turn Revs, I’ve got a set from 2008/9.
Mine had a problem where they locked out due to oil leak, I think it was the damper oil that leaked into the lower leg. Fixed under warranty and fitted a Rev 426 damper instead of the OEM 409 one. Same damper but extra knob so no need to use an allen key to adjust the floodgate. I have no idea if it could have been fixed with a simple seal change or if it needed the whole new damper.
I would strip them and give them a full service with a set of new seals. Should be able to pick up the seals for <£10 and then you just need some suitable grease and oil. If it’s something that needs changing then they may well be fit for the bin if you cant get the uprated parts.