I've been looking at a few classic cars , only thing that puts me off them is like what you say .. has to be reliable and wont fall to bits after a salt laden winter
I would use it all year round , no point in ownership if its just going to sit there
Only one that appeals is the SD1 or P6 but then this would be solid enough for a hash winter
There's no reason why a classic car shouldn't be reliable for daily use, as that's what they were designed for! Pick one that is already in daily use, and you shouldn't have too many problems. Plus, they're easy and cheap to fix if anything does go wrong.
If you're looking at SD1 or P6, then six cylinder Triumphs are a good bet. A 2500 with overdrive is even decent on the motorway, has a nice interior, plenty of space and if you buy a good one and keep it that way is only likely to appreciate. Fuel economy is pretty much the same as an Omega and the other running costs are likely to be much lower. Although that's true of pretty much any classic these days.