[chris vickery]

Wow Casey, whoever did that certainly did a number on them...
Personally, I have tried to repaint plates without much luck. This is certainly true of plates such as yours because the lettering has been damaged slightly.
For plates which are oxidized only, no paint on them, I use a gentle rubbing compound (diamond paste) and a soft cloth to remove the white oxides.
I would leave your brass plates alone, maybe shine them up with some brasso considering the condition.
An alternative would be to use repro data plates and restamp the info. Keep the originals to go with the jeep if you should ever sell it.
This is what I have done with my M38A1 CDN3. Most of my data plates were illegible beyond repair, the only survivor being the serial plate which I left in place as it looks pretty good. I do have a repro to put in its place if I should change my mind.