..after 3 mist coats and 3 wet coats I am not totally satisfied
> with the finish (A bit bumpy.....not glassy smooth)
Orange peel. Achieved by adding coats over not-smooth coats. It never goes away; the lumps just get bigger. But... see below...
So the question is can I wait a couple of days (Or maybe as
> much as a week) and go back and apply another wet coat of paint ??
You can wait years if you want.
Before you apply more paint, sand/polish the bumps out. Some people call this "color sanding". Basically, every coat should go over a smooth surface. Wet sand with 800 grit or FINER. Sand until you can no longer see that there was texture. Be careful of edges where the paint is thinnest and you can easily sand through all the layers to bare plastic.
A good gloss paint job on something as small as a model is a real achievement and not easy to do.
--scott