Latex Paint?

I finished my Honest John a while back and had delayed paints for a number of reasons(mostly color choice) when i finally found the color I was looking for...it turned out to be latex. I had already primed the rocket with krylon and wondered about compatibility but continued with the finish coat anyway. THE FIRsT COAT WAS AWEFUL. Streaks, blotches, fisheye...you name it. So I waited till it dried, hit it with some 400 grit, tacked it and tried again. Mucho Betto!
Here is the question. Should I clear coat...and if so...with what?https://photos.imageevent.com/flying/rocketebaypics/websize/HonestJohnPic1919.JPG

Maybe some clear polurethane or polycrylic? Definitely test the clear coat on scrap material!