they come with pretty substantial clearcoat to begin with...as long as the current coat isn't to nicked up from the shop, I would ride it and put some scratches on it the old fashioned way.
....otherwise you never know whether or not you can provide enough tooth on the current clear coat to let another clearcoat from a different paint manufacturer stick properly.
The last thing you want is a crappy clear coat flaking off because of some paint interaction issue...
Finally - if you do it - it would not be original, and potentially not as valuable.
build it - ride it - smile a lot. Rinse and Repeat as necessary.