VD CRUISER:
Billy B, are you saying grind back about 2" on either side of the seam just deep enough to fill in with 2 or 3 layers of glass and "V" the actual gap so it can be filled up to the ground surfaces, with Cabisil, before glassing over the whole 4" wide area ? Is any more reinforcement required on the inside ? Exactly , and you don't have to reinforce the inside as it shuold have been glassed together at the factory. If not then you would have to glass the inside also. Good luck and if you need anything else let me know.