500N-

I agree with you on the looks of the things.
Nickel plated, shiny silver snap caps with the black rubber primer bumpers are the way to go in the appearance end of things.

As for a spring behind a rubber primer bumper, if it's made of the right stuff, there's no need for an additional spring.
Rubber is a spring. There is a great many different types of rubber-like stuff to make the primer bumper out of, I've made them out of very high durometer elastomer. They've all held up well.

--Tinker