Many Thanks for all the info. It has really cleared up my thinking.

Here is what I am doing so far.

I cut out 4mm ply the exact shape of form 7 on the Guillemot. I will glass it on both sides for added strength and once the pump is mounted will install it as the front bulkhead. I cut a 4 inch diameter circle in it's center that just allows the pumps foot pad and collar to poke through. The pump has 12 twelve small machine screws that hold the top and bottom together. By getting stainless screws that are 1/4" longer I can bolt it right through the plywood with some marine cauking to make the bulkhead water tight and not interfear with it's operation. I used a 90 degree elbow to angle the intake through a 1-1/2 inch hole in the bottom of the bulkhead and a 45 degree elbow at the top to angle the outtake to the side of the deck. I havn't cut the deck yet as I want to think about this for a few days.

Looks like it would be a simple bomb proof insallation using PCV of a high volume pump without taking up room near the foot pegs and no hoses to break. The only problem is that if I needed to service the pump I would have to cut the PCV elbows out to pull out the pump. Hoses with clamps come on and off easier.

How often do these things need service? Should I plan on the diaphragms wearing out every couple of years?