Thanks for the comments everyone. So far the bikes' been cleaned, had a little polish with some 'Wilkinson's' home brand 'T-cut' and sprayed a couple of times with clear coat.
It's spent a week having the BB soaked in WD-40 and now just new a new set of bearings before putting things back together.
The - 'just a quick clean-up' never really happened
I've just come across my first picture of a Sun Mist, it's on e-bay at the moment but lacks the cool top gear lever and the rack. But seems to be in its original state, and from the same era..http://www.ebay.co.uk/itm/VINTAGE-SUN-M ... 2ec8efa342
@ Spokesmann - thanks for the link, I came across your page while a-googling 'Sun Mist' but got kinda jealous by the quality of your frame, a different league from the Mist. We do seem to share the same brakes though, and it appears they were used on the Dawes Galaxy right up until the late '80's. So there's some class in my bike
I'll post a couple of pics when things get put back together,
All the best, Mike