Metal Data Plate Clean-up/Rejuvenation?

Is there a way to rejuvenate old data plates that have gotten faint and oxidized short of replacing them?

If the plate has raised or etched lettering, yes. Delicately clean the plate with appropriate cleaners/paint removers to start with a fresh metal surface. Buff the exposed letters/symbols/borders to a shine. Spray the plate with flat black primer, allow to dry. Using 400 or 600 wetordry sandpaper, ever so carefully sand the raised features. Then coat the entire plate with clear lacquer.

If they are etched yes, if photo printed no. There's an old thread on it #12 http://www.steelsoldiers.com/showthread.php?71629-Anyway-to-restore-faded-data-plates

A lot of us have had these guy make new ones, www.dataplates.net

I don't think mine are the raised type, thanks for the link, it looks like I will be ordering some.
James