I am planning to build a surrey top as seen on antique motor launches for my 17' skiff and am considering my options.
The top will be elliptical in plan form to correspond to the boats cockpit coaming and will match the sheer longitudinally. The frame will probably be 1/2" aluminum tube and consist of the potato chip shaped perimeter and 3 or 4 athwartship bows to give it some crown. The uprights will either be bamboo or cedar. I'm thinking the uprights will have brass ferrule end caps at their bases with a circular plate brazed to them for fastening to deck. The ferrule will be attached at an angle to the baseplate to compensate for the sheer in the deck, allowing the posts to be plumb. Six posts seem to be the correct number. I can install threaded brass inserts into the deck to accept the bases, just outside the coaming. The middle pair of uprights would attach to the gunwhales and couldn't have a base plate, just room for a threaded insert.
I think you get the idea. Has anyone any first hand experience with surrey tops or ideas that might be helpful.
I'm fairly handy with canvas and would like to do the work myself.

Thanks,
Mike