Signs of rust in Engine any Ideas

Last year i had a brand nw engine 408 11.1 compression 98 percent track car ,I was driving it and starting it regularly , the weather got bad so the car sat a few weeks i had a bad ground , so the engine wouldnt turn over enough to get it started , i tried starting it couple days, charged it all night same thing , i did pump the gas trying to get it to fire ,finally it seized and would not turn over i took it back to the machine shop they unfroze the engine , after that i did a leakdown test the first 2 cylinders were not good losing 65 percent and 38 percent, so the car sat 7 months finally the machine shop was ready to look at it, they ripped it apart and found rust on valves, valve seats ,under head of valves,top of pistons,in the exhaust my TTI headers were brand new inside is alot of rust now,The heads definately were not leaking the cooling system is tight , I used cometic head gaskets,The rings did go bad, Maybe gas went through rings and dried cylinders, washout,, I do live in a high Humidity area , South Florida the car is outside but off the ground on a trailer under a carport and covered with a cloth car cover so it stays very dry, I was running 113 race gas in the car, I called VP raceing fuel , they said the gas did not draw condensation because there is no Ethanol in race gas They also said it leaves no residual in the cylinders but would this cause that much rust? ,HAS ANYONE EVER HAD ANYTHING LIKE THIS HAPPEN. Engine was just redone and i dont want to go through this again Any suggestions.