After grinding the stringers down. I will replace them one by one. So I removed the port #1 stringer first and so on. Before grinding and cutting out the stringers I took measurements as best as I could. They were pretty rotted out. Just in case I added a 1/2" to the height and figured I could grind out the excess after placing the frames in. I used two laminated 1/2 birch plys (mat inbetween and on the outsides)((using again the slow set epoxy)). For the frames I used 1X6 T/P that had dried in the garage for over 8 weeks during the summer. Again during laminated I screw the pieces together with 1" screws. The joints between the two ply layers were staggered. The original stringers were single ply.

Here is little man with the stringer on the ground.