@ Bill : This CB was introduced with the Olympia One series back in 1979. From a high level, Electrolux introduced its very first commercial canister vacuum
( Model CA) back in the very early 60s during the intro of the first Model G series. The CA was eventually replaced with the model CB. There was also a CW and a CBW ( for wet dry pick up ) during the early 70s. The CBs were eventually replaced with the CB2000 in 1982 during the initial launch of the Silverado series. The CB2000 was DCD around 1998-99. I will look for Paul, Doug S, and or Tom G to keep me honest on the history and time lines of production.