Finally got all the bits I needed to do this, the cutters to make the holes, some shiny new bolts and a piece of 8mm thick steel plate. I made a template out of plywood to help establish where each end should be in relation to each other. As I'd had several weeks to measure and think about, the actual drilling and fitting didn't take too long. Just need to test it out now.
Friend Nev popped up from Bristol for a quick visit. As a fellow boat owner we had plenty to catch up on. Possibly not what we thought we'd be doing when we were at school over 30 years ago. :)