hello,
my boat, a '91, has those plates bolted to the hull thus transferring the load from the lip to the side of the hull. i'm sure there is extra glass on the inside of the hull where the bolts go thru tho. it was built as an sx and has plenty of glass there. anyway if you are concerned about the gap maybe you should mix up some thick bog when you install the plates. the job seems like it is pretty big an fairly technical. 4 plates per hull, 4 bolts per plate=32 holes to drill. could that be right?
4 cradels set up to keep the boat square, and hulls upright would be nice, but not absolutely essential.