To help inhibit the rust, you can try something like Mar-Hyde One Step Rust Converter.
Generally, u scrape off the excess rust, clean with alcohol and a rag, and then spray the Mar-Hyde directly on the blemish.
It works great to restore the inside of a rusted old chassis.
For little dings on the outside surface however, I try to clean any rust/grime out and then apply the stuff more accururatly by spraying a Q-tip and dabbing onto the blemish.
As long as you do a good job in cleaning off most of the rust, any kind of rust paint (like Tremclad) will work well here.
Good luck + hope it cleans up nicely.