Auto body repair & detailing: auto primering, urethane paint, acrylic enamel

Question
I shot my '30 model A with 2 coats of 2K primer and sanded it between and after last coat.  It feels slick.  Should I go ahead and shoot another coat of 2K or just regular primer and sand again to be on safe side?  I was planning to shoot a coat of epoxy primer on it when I was ready to shoot top coat of acrylic enamel.  Is this what I should do?  How long of a waiting period do I have before shooting top coat?

Answer
Sounds to me that you have a good urethane prime and you are putting a cheap acrylic enamel on top, Why? You have an old show piece, at least use a urethane paint that will last and look good.
Are you block sanding between coats or just sanding. If you have used a fine enough sandpaper, 320 to 400 grit, seal it and shoot it, no need for the epoxy now.