Transom help On a v20 center console

[drj]

Can Someone Please give me some suggestions or ideas of how to do a fiberglass transom repair and strengthened. Here is the problem. The transom was replaced professionally and he did a good job except he left space between the new wood and the old fiberglass. I know how to handle that just grind and re glass the corners of the motor well. From there I'm stuck. The last owner did a botch fiberglass job to shorten the transom for a 20 inch motor. he did not glass the top of the wood good after he cut it but there there appears to be no problem. the problem is where the bolt holes are. Water got in fro the lack of silicone on the bolts and rotted a 3 inch radius around each hole. Can someone please tell me how i can tie in a piece on the top to make it a 20 inch transom again and fix the holes. The transom is not in horrible condition I took an old Johnson 120 off of it and will replace it with a 200 this is not overrated for the boat but I want to make sure with a bigger motor that I do not have any problems.
Please help
thanks