Hey there Seamus - I thought that looked like a Senso too, although I wasn't sure - 80's cylinders not being my area of expertise!
I've been using my Miele today - I was given some bags for it yesterday evening. They were genuine Miele ones too, along with 4 sets of filters. I'm very impressed with it, the suction's so good I have to turn the power way down so it doesn't stick to the carpet!
That Hoover must be well rare - I've only ever seen one UK Sensotronic MK1, which was for sale in a Cash Converters (a type of pawnbrokers over here) a couple of years back. It was complete and a System 5 too, but they wanted £70, so I passed it over...