I've got one of these too, I notice the the bucket sections are bolted to the ends of the jet drive outlet tubes, sandwiching the transom between them, but when I do this on mine, the bucket section sits just proud of the transom by a couple of millimetres, Do the outlet tubes need trimming flush with the outer face of the transom?
This would mean the buckets would be fitted flush against the transom making it more secure and easier to seal.