The vibragroomer II was orginally disigned for the Selfpropelled upright, which was intorduced at the new Orleans Eureka Convention in Feb. 1979. It was soon changed
to the vibragroom II, as the first one had sleeve bearing and
could not hold up to the heat stress of the 6.5 amp motor in
the self propelled machine. I believe the model was a 5060 A/
B series. So the Vibragroomer II came out on the upright with
Ball bearings, like a Hoover Convertible or the Helixical Steel VG I, with ball bearing.Then the VGII with Ball Bearings
was adapted to the Roto-Matic power nozzles. Not sure but think that was later during the year of 1979,Maybe 1980 !!!
NORM