Hi Philip.....
If I remember correctly, the first line of Eureka canisters featuring Roto-Matic powerheads was offered in 1973. The two-motor vacs were called Eureka Power Teams, and the group consisted of three models: One was a basic harvest gold canister from the 1600 series (known as the Sweet Sixteens) - this basic unit had no "Control Panel" for adjusting suction, and no full bag indicator. It was one of those boxy Eureka canisters that had a Tool Pak on top - a design which was later known as an Ironside (same form) in the 1980's. The next Power Team was similar to the harvest gold version, but had the deluxe Sweet Sixteen canister in burnt orange. This version featured a Control Panel with a suction dial and Full Bag gauge. The most deluxe Power Team in the debut line-up was basically an 1800 series Empress Two "FastVac" married to a Roto-Matic power nozzle. It had racing stripes, a Suction Control panel of 6 pushbuttons, and a Full Bag indicator. It was brown in colour if I remember correctly.
All these "Power Teams" were given model numbers in the 1200 range, if I remember correctly.
All of Eureka's first Power Teams came with basic Roto-Matic power nozzles featuring a faux woodgrain inlay on top and no headlight. The brush inside was not a Vibra-Groomer - it was a basic Eureka "Disturbulator" with one row of bristles and one red plastic beater bar.
In 1974, Eureka added a fourth Power Team - a budget version which was all red and consisted of a classic Eureka Princess (H Bag) combined with a red Roto Matic powerhead, minus the faux woodgrain inlay. Consumer Reports rated this as the top power nozzle canister and a "Best Buy" because it was so inexpensive for a top performer. In this year, Eureka added a headlight to the deluxe Empress II Power Team.
It would be important to remember that the name "Roto-Matic" was originally used for Eureka's barrel-drum canisters of the 1950's. These never had power nozzles. Eureka just recycled the brand name for their power nozzles over a decade after the last Roto-Matic canister was produced.
Hope this answers some questions. If anyone has any corrections to this bit of foggy Eureka history - please chime in! Norm????
Eurekaprince