Spongy wood ain't good
I had almost the exact same problem when I replaced my engine bracket on my Oday 23. I too bought a new mount from Rudy, and when I removed the spacing wedge, big chunks of fiberglass wanted to fall out. My spacer also seemed to be built around a piece of wood. The wood I could see looked ok, but I could tell there was some interior rot because when I removed the bolts, it looked like they had dirt on them. Here's what I did: I removed all of the loose or semi-loose pieces of fiberglass. I bought some West Epoxy and some high volume filler. You don't need too much. I bought a "touch up kit" instead of the big containers. I had to use it all up, but it was enough. This stuff is nothing short of amazing. I mixed up the epoxy, then added the filler. I put on a very thick coating of epoxy in the now big open space in the middle of the block, coating the wood and sound fiberglass. I built it up by adding a few more coats of epoxy. I kept it up until I had a rock hard coating of epoxy around the whole inside, about half an inch thick. I then put one more thin coat of epoxy over the whole mess, including the sound areas that I hadn't yet touched; this gave me a waterproof coating on the side of the spacer that mounts against the transom. This whole thing is now bulletproof. I love Rudy, but he charges market rate for skilled fiberglass work. It is much cheaper to use the epoxy. It was the first time I ever used the stuff; after a little practice it was fun. The best part is that you don't need to worry about how it will look because no one will ever see it! You may need to replace the interior wood block if it is completely rotten. If so, try and work it so that you don't have to drill through the epoxy. When you remount the spacer, don't forget to seal it against the transom with silicone. Good luck.
