Dear Stephen.
We have a 2006 365 GL from new. Like Godwin, I am unable to load your pictures.
Our sump remains dry even if we get caught out in a challenging windward beat.
Only time it gets water in it is when we drain the fridge, when the bag of ice melts. There is an on-off tap under the cooker that controls the drain which will drain into that sump, but that of course is fresh water.
I do keep a watch on the keel joint when the boat is out of the water. It is not a tidy joint, but we have never experienced a leak. The bolts inside do have a slight rusty stain on them from, what I think is damp from the fridge water drain.
Sorry it doesn’t give a definitive answer to you, but it is a lovely boat to sail.
Regards Chris