repairing gelcoat on an older canoe..

Hi, 

I have just been given an older mohawk 16' canoe. It's in great shape
apart 
from some scratches and several large patches where the gel coat has come 
off and the fiberglass has been exposed. Its chopped mat layup so i think 
that means its polyester?  Anyway - whats an economical way of repairing 
the exposed mat sections? Should I just get some epoxy and paint it on and

sand it flat and repeat until its all flat and in line with the remaining 
original gel coat? What about painting it? do i need special paint,
surface 
prep?  and how expensive is it to piant? since its an older boat it's not 
worth putting that much money into it..   

Sal