Andy, hello.
I'm in the process if installing a Lewmar HX1 into our P325, Sandack. I've also gone back to the main batteries for the full cable run as I wanted an isolator switch and 80A breaker under the chart table where our other big switches are. I have the windlass contactor (and wireless receiver) in a tupperware box, tucked away in the port side fore cabin stowage, close to the chain locker, with the socket for pendant in another sealed box under the lip of the chain locker.
Sadly, the chain fall intersects the bulkhead so I have excised a chunk and fabricated a chute from 0.7mm stainless sheet sheet which was fairly easy to bend. This chute will be glassed in from the fore cabin side to keep water out.
Hard to picture and no photos yet but you are welcome to visit us at the Marconi Sailing Club in Steeple, Essex. We will be ashore for another 4 weeks or so to complete coppercoating, windlass and some headlining.