the side of the can should tell you what type of finish it is, whether it be enamel, laquer, acrylic, polyurethane, or what-have-you. you really should find out exactly what you're spraying. this will keep help you avert disaster if you do recoat.
why can't you just buff it out now? four coats should be plenty of coverage if it's even. i've done a guitar and a bass with rattlecans, and everything has turned out swell so far. it just depends on the quality of paint you get. about the best i've found in a rattlecan is duplicolor.
if you spray laquer now, it will probably wrinkle the current finish. laquer solvents will eat through just about any finish. you might find yourself doing the whole thing over again if you mix types of paint like that. i'm not too well versed in nitrocellulose, but i know this is the case with automotive finishes.
it'll be hard to find tinted clears in a rattlecan. if there are any good ones, i have yet to find them.