I also managed to get the cockpit rim out in one piece, using the same technique from the underside of the deck.

As you can see, I experimented with making the back of the riser the aft bulkhead, mainly to minimise cockpit volume and make emptying easier.

This has worked very well, although to my surprise you still need a backrest, however since I made it after the hull and deck were joined, I had enormous problems glassing the back of the bulkhead, and also had some water penetration here, so this is a good opportunity to clean this up as well.