I have used Avon CR6ZZ on the road in all weathers on my Porsche 912 - for normal use and for rallies. I can recommend them highly
These tyres are really very good - far better than any normal road tyre - in both the dry and the wet. The size I used came in two compounds and I used the softer one. Looking at their site the only size they do in '80' profile is the 155R15 - which suits a 4" - 5" rim. For the wider rims you have you would have no choice but to go for a '70' profile - they produce a 175/70 and a 185/70 15. On my 1967 Porsche I used the 185/70 as they were an 'in-period' option but may not be for your 1950's saloon. However, all three tyre sizes I have mentioned share the same rolling diameter of 635mm, so they would all look 'correct' on your car I am sure.
http://www.avonracing.com/road_legal_page.aspx