Hi mate you could try getting in contact with TR Calibrations down near Prestons.
I think I got my 34401A calibrated there for around $200, it was a NATA accredited cal. (adjustments on the ACV ranges were approx another 200 on top, it was a meter I repaired)
My memory could be waaay off though, I can't find the darn quote in my inbox anymore. For the 34401A they just whack it on their Fluke calibrator IIRC.
I've got the report somewhere...if you'd like to have a look at it I can upload the data. (might be a couple days though my garage is a mess atm)