I'm sure there are many different opinions on this topic, but since I also have a '52 220, here is my input.
First of all, I'm not sure what a Safety Rim looks like. Three of my rims are similar and one is, I assume, is an older version.
I've never had an issue.
I drive quite a bit and also wanted a radial tire, but finding a radial with similar physical dimensions as the original bias-ply is a challenge.
I think a 185/80R15, or a 185HR15, are good choices. I have had a set of each. I buy my tires from "Diamond Back Classics" because they use modern production tires and will add the 2.5" white wall that I want.
This is not a common size and my last set had to be special ordered from Europe.
The two brands that I have bought were Federal and Vredestein Sprint Classic.
It has been 5 years since I last bought tires, so things may have changed quite a bit.
Another company that may have a size you need is Coker. But I've had great luck with the Diamond Backs and they have always been very helpful sourcing the size I need.
Scott