My old Cosine Wherry finally got a scratch in it deep enough to worry about fixing; embarrasingly enough coming off the "garage-sale trailer"...

It dug through two of the three layers of 6oz glass. After sanding it out I realized it does not go to the wood; if I'd known I would have just varnished it over for the summer, this boat is up for a re-coat next winter.

Should I add three layers of glass back into the gouge I sanded? And will it blend under the varnish without showing the glass where I sanded through it? Any good tips for blending it back in?