the lettering came off very easily with a heat gun.
I concentrated on one corner of a letter for about 15 seconds and then heated the rest of the letter for 5 seconds. Using a plastic scraper, I worked the corner until it rolled back about 1/4' and then with my fingers was able to pel off the whole letter in literally seconds.
The shadow, well, that's another story.
Gum Wheel - I should live so long. I gave that up quickly.
Acetone and adhesive remover - Waste of time.
Alcohol - removed the faint trace of residue, but that's it.
320 Grit wet/dry paper applied wet - worked great. I went to store and picked up some 600 Grit paper for fear that the 320 may be too aggressive. That was somewhat slow going but not too bad and that did the trick.
Now for my next question - I am going to buff the entire stern before the new lettering is applied. Definitely NO WAX at this point. What grit wet/dry paper should I use to remove the chalking of the gejcoat?