pretty much that will happen, you can paint it with bare metal gray but the dot 3/4/5.1 will slowly remove it, you can touch it up etc.
another option is use a product like rust away on it. wipe it down then oil the surface with silicon spray or wd-40.
as an example of using rust free; this is not a convertor it is a muriatic acid that chemically eats oxidized metal, and removes it leaving the unrusted metal behind.
before:
rust free, spray, soak, wipe.
Gibbs lubricant(similar to wd-40)
hit it a couple more times after
done:
I've used rust away type products on tons of things and had good results.
it takes patience but I've restored some stuff to new and even managed to keep most of the original paint and factory markings on parts just removing rust. I've also saved some very rusted chrome parts, using a soaked micro mesh cloth with the rust free product working it into the surface cleaning up with alcohol and then lubricating the surface.
