I finally had to do something about the hole left behind by the old stereo. I was thinking about putting a tray or box in there, but couldn't find anything that looked like it would look good there.
I decided to enlist the help of a machinist friend to carve me something out of CNC.
First we cut some aluminum stock to fit over the hole.
Then mocked something up in Adobe Illustrator using the HemiHead font.
I have an old oven in my garage that I do hobbyist level powdercoating in, so I decided to coat it black (along with some other bolts for the boat).
25 minutes and 350 degrees later, cured gloss black.
Today I brought the coated plate to my machinist buddy along with the file. The end result is pretty slick! I'll follow up with a final photo once I get it mounted.