Anyone out there had any experience replacing a gel coat exterior ?

Sorry...I was a bit late to your post. Gelcoat can be painted with
gelcoat. It's a process similar to painting automotive lacquer. It's
probably an easier solution for you at this point although it will
require a lot of sanding and possibly filler in the deep scratches.
The trick for the gelcoat is the use of a reducer specifically
designed to "air dry" the gelcoat. Acetone or lacquer thinner will
not work and the only way you can get the reducer (in small quantity)
is from a shop than actually works with fiberglass. I use a mix of
1.5% hardener and 5% reducer when I work with repairs and it seems to
do very well for me. Once it hardens, it will require color sanding
with a fine grit paper (400 to 600) and machine buffing. At that
point...it looks the same and has the same durability as it did when
it came from the mold. Just my two cents.