[peterb]

You probably want to move this to another forum.

In answer to your question the obvious things are the shape of the transom and deck, as well as the engine.

Check the deck and transom for soft spots & moisture. Check the compression on the engine.

Also, look at the shape of the gas tank and the elecrtical wiring.

Good luck. Please feel free to take tons of pictures and then post them here. You will be amazed what the pictures reveal that you might not see the first time with your eye. Also, there are many members here who provide you with excellent feedback.