Winchester.....I bought last Spring the Coker Radials that look like Bias Ply and they are running really nice. NOT as good as 225's as noted here, but it gives the car a lot more stability & looks original !
I've got Coker wide white wall radials 600x16's on our '39 CS. They've been on for just over four years. Originally I ran tubes but the stems kept chafing and leaking air so, I took the tubes out and I'm running the radials tubeless. I do a lot of long distance highway driving with the '39 CS and the radials really make a big difference in the ride and handling.
I went tubeless on 4 1/2" wide stock rims for my 1/2 ton pickup using four "Kumho" 225-70-R16's from Americas Tire for a bit over $400.00 down the road. Couldn't be happier. Rides and drives like you want it to.
I have diamond back radials on several of my V8.It is my experience that they greatly improve the ride and handling but make the car much harder to steer.Ijust took the DB radials off my 41 sw and replaced them with Coker classic 600:16 due to hard steering and rubbing the fenders.The car steers much easier ,looks better,no fender rubbing,but rides harder and does not handle as well as with the DB.Phil
We run 205 R 16 radials on a '38sedan.Drives very well and stable.They make the steering a little heavier at parking speed and a 4"rim is just wide enough.Outside profile about 650 x16 so gears the car up a little.The same tyres as on LandRover Discovery which you may not have many of in your part of the world.Cheers.