Greetings - I would suggest strongly against covering the hull with glass. Unless you are prepared to add enough layers to counteract the movement of the wood and also cover it from the inside as well - impractical.
I have replanked my 70 y/o Alden ketch
but first insured that the ribs, floors, stringers, clamps and shelves were all in tip top condition along with replacing all the iron bolts. The planking was bronze fastened and was all sealed inside and out with CPES and the seams were splined as well as all the butt joints were scarfed. Of course, then, there was no longer any need to even consider using any fiberglass.
I don't know if a double planked hull could be splined in situ - only the outside layer being accessible. I think you should start with a full evaluation of the hull to find out where it is leaking and why. Don't just do "something".