[macojoe]

The transom has about a 2" curve in it from the center to the edge. when I put my bracket on I had to make 11/2 " wedge shims to put on each edge of the bracket as it was form a 23 Seacraft and they are stright across.

Heavy woven is stronger then a thick mat! and The more layers you put the stronger it will be.
I would let each layer dry before I lay the next layer. it doen't take long for it to dry and will be much easier to work with!
If it were I , I think I would use brand new wood for the stringers!!
I would glass new boards right in to the transom right along the old stringers and bolt in to a good spot on the old stringers.
Then when you want to do the whole job the right way you have something already in the transom without having to mess with all the work you just done.