I just replaced this same transom but on an 18' 1977 holiday. Looks to have identical shaped wood and splash well. I too noticed the bow in the skin. After replacement, the skin pulled in tight. For the motor pad, I used 1/2 inch ply with two coats of gluvit, then followed by two coats of rusto gloss white industrial. Gluvit was used as i already had it for another project. Paint was added while gluvit was still tacky. It was a rush job to have the boat on the 4th so thinking I would save time the splash well was left on. Before it was over, I really wished I had taken the time for splash well removal.
After seeing where the original transom wood took the brunt of moisture and rot, I have some thoughts to share on sealing corner caps as well as drilling a drain hole or two bottom side of rails and 3-4'' infront of corner caps.( Maybe a pic would better explain) The slope on the gunnels guide water out to the rub rails. With the bow tilted up, this sends water back and under the corner caps where it then runs down the top outside corner and edges of the transom wood. My son and I witnessed this while working on the boat with the nose sticking out of the garage door during a rain. My 95 SFM caps were sealed and it showed with zero staining or wetness in the top corners of the transom.
