Alan, Michael, Mark, Charles and Jelly, thanks for the feedback and comments. Points noted and profile updated, Charles. In answer to your questions, Alan...
1 Yes, gear ratio, I am sticking with what I've got. The 1.81 ratio was to ensure the tub would get up onto the plane. It does it easily with the 1.65 so there's no no need to change. I will now go shopping for a second prop and will see what works. It will be interesting to see if the originally spec'd 23" does better or worse than the 21". I'll let you know how it goes.
2 What's WOT? The peak revs that are looked for in the book are 3,800 and we can do that but no more before there's nothing left on the stick. It's at that point we hit the 35 figure.
3 Airborne once or twice. But apart from it making Di cross with me for doing so (my sciatica is marginally better, but it aint that good), I'm not that keen on doing the flying thing. I read somewhere on the forum that landing from a flight seemed to be part of the cause of the failure of the Bravo 3 legs. The load that the prop puts on the delicate insides of the leg seem to be too much when it bites again.
Interesting comment about the Floscan and Merlin. I have got prices from both Merlin and West Marine and the gap between them, after taking VAT and shipping etc into account, is about £100 in West's favour. For that sort of money, I am inclined to go to Merlin because of the difficulty of back up from the States. I buggered up a hydraulic line olive on the Bennet trim tabs when I fitted them and getting a spare, when I get around to replacing it ,will, I feel sure, be a pain.