I came late to this site and too late to this build log to do me any good. I have ‘finished’ my Model Shipways Constitution build and had the same problems with the transom as it seems everyone else has had. I am afraid this will be a little long and perhaps boring. I hope not. About 35 years ago I built the Mamoli USS Constitution. It took about a year and a half. About 4 years later I built it again after the cat knocked it off the shelf and broke the first one beyond repair. I started this one about a year ago. I casually mention to my son that there was a new, bigger and supposedly more accurate Constitution model being offered. He said I should build it. I said I was getting too old and stiff to build anything like that again. He said I was retired and had all the time in the world, so I started on it. After a short while, I complained to him about how the model was almost a scratch build and how vague and unhelpful the plans were. When he said he guessed it was just too hard for me, I knew I had to finish it no matter what. I have only hand tools, except for a cordless drill but as a retired art teacher who did some wood carving, felt I could handle the job. It would just take longer. I am not an experienced model builder but built some plastic square riggers as a kid and years ago did do the two builds mentioned earlier plus other wood models: one of the HMS Beagle and a couple cross sections of US frigates. On this one, I noticed after assembling the bulkheads on the keel frame, that some of the tops were not even and I’d have to figure out how to make the deck straight when I got to that point. After I assembled the transom section and saw that it was going to make the deck even more messed up, I quit and started over with a new kit. Being forewarned of problems that could occur, I did my best to avoid errors I made on the first build and made sure the transom parts fit the rest of the model as shown on the plans but found that even so, the deck and side walls of the ship were still going to be off. I ended up modifying the kit so everything would fit even though I knew in my heart that the model would not be as true as I hoped it would be. Now that I have read parts of your build and saw another on line build go astray, I realize that it must have been an error in the kit and not completely to my ineptness.
I hesitate to show a picture of my build after seeing how wonderful your build is going but here is the aft portion. At one point, I was determined to finish it even if I had to avoid calling it "The USS Constitution"