Marcel4tI'm probably too late with my response to your post. But for WIW I did the transom on my 73 19'6" and cut it out pretty much exactly as Fish Head did.I saved the outside skin and after cleaning all the old wood out I cut a piece of 3/4 plywood that went across the outside of the transom. Screwed the old skin to the plywood and screwed the plywood to the transom. I then filled the transom with Seacast. After everything setup I took the plywood off and feathered the seam back approx 3 inches on both sides of the cut line and glassed it back in. As well as glassing a new cap on the transom. Sanded it all back in, got it looking real nice and the sprayed it with gelcoat. After much sanding to the gelcoat to 1600 grit I went to the buffer. It couldn't have come out any better, it's rock solid and no more worries about wet plywood. I did the rebuild in Jan, Feb 2008 and it's just as good as the day it was finished.Hope the info helps and I hope yours came, or comes out well.