My boat was supposedly painted with Imron and then the License number was painted on over that.

What might be a good way to remove the numbers without damaging the Imron?

i just took numbers off my magnum.... i used a medium cut polish and my dewalt wheel and buzzed them right off and then just polished right over them....I have used easy off oven cleaner in the past that works good too........

I would try to wipe/scrape the numbers off first. If the lettering doesn't come off quickly, you will have a halo from the difference in gel thickness from buffing. Gel is usually softer than paint and will be removed quicker than you will be aware of. Check out this previous thread:
http://www.offshoreonly.com/forums/s...d.php?t=126865