"Eureka Vibragroomer's"
have 3 series. The "1" has the aluminum extruded twisty beater brush roll bar.
It resembles a large twisted "Churro" in a way for lack of a better description.
The beater bars are steel, and the brushes replaceable.
The "II" is a steel round brush roll with formed in beater bumps and replaceable brushes.
The "III" is the same, but has two rows of brushes.
Eureka wooden beater bars were not called vibra groomers, but they do the same thing. The brushes are replaceable. All their uprights before about 1977 used them, and the first rotomatic power teams that came out then as well. The premium models in the line up had the then new vibragroomer I.
Rainbow, Fairfax, as well as Compact used the first power nozzle design. Airway may have in their adapted Eureka upright head power team.
The head shell had a restyle with the Express line of Eureka power teams, and a face lift for the steel bodied 1700 seiries, ironsides, and Quiet Clean canister power teams.
In my best guess, the steel Vibragroomer vanished with the debut of the plastic bodied "World Vac" and "Rally" line of canisters. Subsequent brush rolls were extruded nylon composite.
