Front cover missing
By the process of elimination, I thought the Sensortronic began in 1982 and of course early models had honey-beige tools. The photographs here clearly show dark brown and as catalogues always showed out of date photographs, the brown tools must have been available for some time prior in order to be shown here. The reason for out of date photos was, I might add, because they were requested from manufactures a good deal of time ahead, meaning by the time a new product was sold, many changes could have taken place since the original photo was taken. To this end, I would suggest the catalogue is from late 1983.
I have a notion that the Sensortronic changed from 1,2,3 etc. to 10,20,30 and so on around late 1984. I seem to recall owning documentation from this year which mentioned the changes. One thing Hoover didn't do until relativly late in day was to use a static hose on the base models, rather systems 10,20, and others still had stretch hoses on very early examples. These beefy cleaners were very hard to pull round by a stretch hose and the static hose was a welcome change, yet the oddity of these models (and forgive me if I sound surprised that Hoover had yet another quirk, because I'm not) is that cleaners made for the overseas market can be found with the large, singular operating pedal which was present on the first Sensortronics, and yet had static hoses. I am not sure if the static hose was included on overseas models from the outset, or if production of single-pedal models carried on after the UK cleaners changed to two small pedals.
The Freedom Electronic did indeed carry right on into the 1980's, finishing off with a black set of tools during the last production run. It was a very dated cleaner by then and I never understood why Hoover kept it going.
The Goblin cleaner mentioned must have been the last of it's type; earlier and more popular models were cream or green (electronic). This one is of a lower wattage and with no outstanding features, which is why I think it was one of the last. Also, this would have been around the time that Shop-Vac bought Goblin and a lot of streamlining took place prior to new models being built.