I joined the pieces because I had 4" Fir on hand. It would have taken a wide board (and a lot of waste), to cut it out in one piece. But the joint (a simple overlap), isn't a structural issue.

I haven't done that much steaming or laminating but of the times I have, there's quite a bit of spring back.

These cut ledgers fit the curve like a glove and will be easy to install (I think...). This joint is overbuilt (I think), when it's all set. The old cockpit was fastened directly through the mahogany and into the coamings, and a bed of sealant(leaked long ago). I like the idea of a solid joint, that even if the deck caulking joint fails (and it will at some point), water will not get through.