Carl:
You are going to love this model. I flew mine again yesterday and after a slow victory roll and climbing 180 deg turn the ohhhs and ahhhs from the pit area were abound!
I would suggest replacing the mounts for the retract servo with hardwood, and before doing this reinforcing both the inboard and outboard ribs with light ply as far forward (to the aluminum rod) and as far aft as you can go. Then epoxy them in liberally! This will reinforce the whole area, and make it secure.
As for the letters, I confess that I "borrowed" them from a PICA 1/5th model kit that I have. They are in the markings of Air Vice Marshall Johnnie Johnson, one of the RAF's most highly decorated Spitfire pilots. He led the 144th Canadian squadron over the beaches at Normany in 1944. I have a signed Robert Taylor print by him and so I've always wanted to build his spit.
You can order all these decals from Pica (www.picaweb.com).
As for the gloss, I wish that it was a flat finish. I am searching for ways of taking the sheen of the covering, but have not found a technique that works yet.
Good luck with your spit, send me pics when complete.
-Paul