Ike your a handy dude.
On my old boat they told me to put the HIN on the INSIDE of the transom, up high in the Port Stern. I wrote it in the Aluminum with an electric pen and wrote over that in india ink. Real easy to see and read.
In my case I dont think it matters any more. The poor old thing is starting to show some serious corrosion. That's the reason for the planning of my wood Jon boat.