Wow, those Converto-Vacs are RARE!! Unfortunately, like the Philco Automagic and Control Towers, it was a good idea but the design never caught on and was ahead of its time. You could say the Converto-Vac was the Sanyo Transformax of the 1960s, except in a more full-sized version! I last saw one on eBay in 2002, and it went for more than $300. Needless to say vacuum collectors are practically fighting over them and they're becoming even rarer by the minute.
Now for the details (if memory serves...):
The Converto-Vac was built on a basic square canister platform, however, it also had a built-in power nozzle and even a headlight, which explains the "brushes under the wheels." The bags were in the compartment like a canister of that time, so it looked like an upright with no outer bag! It was also clean-air I believe. If the user wanted to use the tools he/she put the hose in the canister (not sure whether it was the front or back) and I think even the handle came off like the Kirby machines. I saw an ad for one on eBay from 1965, however I can't find any now or any pictures from vacuum cleaner Yahoo groups, otherwise I'd point out to you what it looks like. A very peculiar-looking machine...
Anybody have any more information on these, pictures, etc?
--Austin