Dog Dish Grip on Reproduction Steel Wheel

Hey,

I bought 15 inch 63 series wheel vintiques steel wheels, i also bought reproduction dog dish hub caps. Problem I have is I don’t trust the grip the cap has on the wheel. It snaps on there, but when I squeeze it in the right place I can take them off with my hands, with not a lot of effort.
I have an original steel wheel laying around, and put them on there. They fit way nicer since it has four tabs on the rim. Has anyone else had to deal with this problem and has found a solution, or has an idea to improve the grip of the dog dish on those rims?

Thanks in advance