I hate asking stupid questions: primer removal

[purzell]

But I do seem to feel like alot of them are stupid...

Anyhow I read the forum for several hours today getting side tracked on other folks' builds, trying to find the answer to my question....

I am cleaning up the truck getting ready for a body guy to sand blast some of the more rusty areas to patch some holes.

I tried the CLR method on the paint to see what would happen. My truck is mostly in white primer. Some areas the white primer thinned out with multiple attacks with CLR and a scrubby sponge. Mostly the white primer held up.

So my question is: besides sand blast any way to get through that primer stage? I think I found some painted on numbers and lettering underneath part of it and I really want to know what it says without loosing it all. My truck was supposed to be a Forest Service or gov't truck and it would be cool to find some markings under that primer.