The lack of air vents on the hood hints that this Eureka is from the early 1970's. By 1976, the low end Eureka Dial-a-Naps had cooling vents on the hood and a push button foot switch, not a toggle switch. These were also renumbered to reflect a 1400 Series model number by 1975.
The Harvest Gold colour matches the first Eureka Power Team canister in that colour, which made its debut in 1973. I would therefore date this vac at around 1972 or 1973.