Right...
The Contour was launched in 1991 to replace the 600 series. It was intended to be launched alongside the Glider (which originally replaced the 500 series) however it actually ended up being launched almost a year after the Glider.
Originally, there were 2 models - a white, 600w single speed model and a green 800w "boost" model. At the time, they were the most powerful cleaners on the market, and were advertised as such. At £139, they were also one of the most expensive cleaners on the market at the time.
The original Glider/Contour range looked like this:
Glider z1250 - white, single speed, 600w, no on board tools
Glider z1260 - blue, 2 speed "boost", 600w, no on board tools
Glider z1270 - pink, 2 speed "boost", 600w, no board tools cord winder
Contour z1410 - white, single speed, 600w, on board tools
Contour z1450 - green, 2 speed 600w with 800w "boost", on board tools
Somewhere around 1992, the z1450 was dropped and replaced with the z1460 which was virtually identical apart from the addition of full variable power and the removal of the boost button.
The original Contour and Glider series came with a horrible friction fit handle release that was later upgraded to a full release pedal as the orignal had a tendency to wear out very quickly.
About the same time as the launch of the 1460, the Airstream was launched, which was 1000w, grey with full variable power and higher level filtration. I think Electrolux were going neck and neck with Hoover here as the Turbo 2 had just been launched and was also 800w (like the contour), so the existence of the Airstream was purely to keep up with the "most powerful cleaner on the market" ad campaign, which was later replaced with a rather vile ad campaign featuring magnified dust mites printed on sales stickers on the machine.
There were a million and one varieties of the Contour during the 90's - boost, varipower, ESP, Contour 1000, Contour 2, Airstream, Airclean etc. etc. It's hard to keep up with them all. I believe the model you have there is from the main run of the first ESP models, from around 1994.