MaxQ
Tripoli 2747
I had the same wrinkeling problem on Apogee Saturn 1B and on th bottom third of my Centuri Thunder Roc.
That aside this is one awesome build you have going. I am verey impressed and a little jelous of you skill.
....had the eact same problem last year with my Sheris HR - Gemini Titan. Never had problems with the old Krylon.