I seem to recall the earlier blue Vax uprights came supplied with a wall bracket, on which the wet cleaning tanks could be hung when not in use. They were indeed bulky and awkward to store, and on top of that you had the additional hose and wand to find a home for too.
Another item specific to the uprights was the priming plate. This slid onto the wash tool, sealing off the suction to get the flow of shampoo started. Even the gravity fed canister models didn't need this, as their solution reservoir was pressurised (after a fashion) by the motor exhaust.
The whole setup was rather novel in theory, but incredibly kludgy to set up, use and take down again afterwards. My mum found this to be a huge disappointment, having been under the impression it was simply a case of filling the cleaner up and using it as an upright for shampooing. Had Vax been able to design the machine to work in that manner, it probably would have been far more successful than it actually was.