Stuart,
I suspect they are of similar design to the chainplates on our 2004 36 (four through deck bolts), which also leaked a little.
Removing the trim under the chain plate in the cabin and tightening with a socket stopped it for a while. Eventually I reseated with sika around the top of the bolt on the outside.
As I recall there was one of the four bolts that was significantly displaced relative to the hole through the trim in the cabin. Fortunately it wasn't this one that was leaking. Getting a socket to it was going to be difficult.