How to repair the plastic outer skin of the Tufskin build ?

[Arno13]

Hi all
On my Hybrid formula, I had a very small dent but some water had leaked in and I had to cut out about 5*10cm of plastic area.
The board dried now, the glass surface is quite neat (no repair needed) but wat should I do for the surface ?
Will white gel coat do the trick ? (I see on the website that it is a thickness of 4mm that I have to replace). Or should I better put some more epoxy + fiber glass, sand it down and paint it ?
But I wonder how it's gonna mix with the contiguous plastic skin in the end.
Thanks in advance and happy new year every one, wishing you all steady winds ;-)
Arnaud