hey! My new viscount Mystery from the uk

Hi Ollie - welcome to the forum. I'm on my phone at the moment so pictures not very big but Aerospace Pro looks quite possible. The Colarado is lugged unlike this one.
Hope it rides well!?

It looks like a late-seventies Aerospace Sport/Pro/G.P. with the fillet brazed frame. There doesn't seem to be a lot of difference between these models. The 'suicide' brake levers suggest Sport or G.P., the Crane RD suggests the Pro, which was top of the range, but the Sport tended to be fitted with tubular tyres (tubs / sew-ups). The forks are original steel ones, so no worries there. SR bits, Weinmann brakes, Lambert levers (there must have been a BIG stock of those) and Olimpic 64 pedals almost certainly original. Likewise the wheels (Viscount or Shimano hubs?) Saddle looks as though it might have been trimmed? Probably Middlemore or Viscount-branded Middlemore, which would have been fitted originally. Unbranded seat post probably the Lambert/Viscount copy of a Campagnolo one. Worth checking, as with all lightweight steel bikes, that the stem and seat pin aren't stuck. Although if the bike fits you as it is and you don't intend to get it professionally re-painted, it doesn't matter too much. As it's so original, the bike will probably have cartridge bottom bracket bearings. These are standard industrial bearings, if they ever need replacing, but can be pigs to remove. I like the black, but probably not original for your bike. Enjoy! And bring it to next year's Death Fork Rally if you are in the UK.
A bargain for a case of beer (Pete might disagree).

I agree, a great find. I particularly like the look of the sloping shoulders on the forks. I reckon you won't regret spending a bit of time and a few bucks getting it spick and span. b