great build. with the paint...your temps are a little on the low side but are workable , you might want to try warming your cans of paint up in a bucket of warm water or the sun for a few minutes before painting. never use a can thats almost empty. they start sputtering. also try thin even coats, try not to get the wet paint too thick. if you have ever touched a metal piece immediately after spraying it you may notice that its cooler, that drop in temp (from the release of the paint)can peal up freshly spayed coats. also as you near the final coats up to the clear coat, i would not stop with 600 grit, 800, 1000, 1500 maybe. hope this helps.