I got my VRM 10 used, with the rotary option already installed. I sent it straight to Stanton Magnetics for a tune up (they found a couple of minor issues -- dirty connections, pots, and replaced them as needed, plus put a brand new faceplate on it, all for under $100) and now its still like brand new.
If you call Stanton Magnetics in Florida, USA, they can hook you up, but you have to be a bit clever with them. Tell them its the only mixer you truly love, but if they cannot cough up the rotary kit you might just switch to A&H...your knobs will arrive soon enough.
I have tried other rotary mixers -- Rane, Botex, etc., but for me the VRM 10 is truly in a class all its own. Once mastered, that is, because one thing about that powerful eq section is the ability to truly mess up a mix very very quickly just by touching the knobs too much! The thing I learned is that a patient ear and a precise touch are far more important than headroom and big rails.
Same goes for the Xone 92 (the 62 is not comparable to the VRM 10, IMO) -- you have to be really patient with yourself when listening to your records and messing with the EQ section because you will find that you have never really completely heard your records if you have been using a straight 3 band EQ.
Hands down, that's the best thing about those mixers (Xone 92, VRM 10 and similar) -- its like obtaining a brand new record collection right on the spot. The new possibilites are endless, and mixing that same record is a new experience even two years later.