Finally got my boat registration numbers on the boat... it really wasn't as bad as I thought it would be. I ordered the custom numbering from BoatUS (thanks for the reference Mike). They are the reflective white color... standard 3 inch numbers.
I started by trimming the excess to the very top of the numbers as close to the actual numbers as possible... straight line across the whole way. To deal with the curve of the hull, I did a V cut between the sections so I could adjust as I go. The numbers are not the wet install - they were a dry install per the instructions from BoatUS.
I dug up some 1.5 inch blue painters tape to act as a spacer from the rub rail. I measured back about 10 inches from the dock light and found a rub rail screw that was my "starting point" from the bow. coincidentally, there as anothe rub rail screw on the other side that was within 1/4 inch of my measurement - so both sides match almost perfectly. Get the tape up and make sure it follows the rub rail... then I peeled back one set of numbers at a time and just mounted them up there. it's a painstaking process -- take your time. I had a 2nd set of hands to help me out when I needed it - that helped alot also.
They came out pretty good. The font I used also seems to hide a couple of misalignments pretty well.
Spacer with blue tape

Installed looking straight on

Installed looking down the hull a bit
