The fish master top is just an idea - I don't know any thing about them and the design looks weak from an engineering perspective.
In fact, I think their final hinging point(the one on the top)is unnecessary an a weak link.
By buddy's Carolina Classic 25 has a hinging tower, and it does not shake rattle or roll unless I'm up there doing the swordfish dance to some blaring Santana

No, it really doesn't even move even under those conditions.
It uses specialty pins similar to these to lock it:
http://tacomarine.com/item--Breakawa...away+pins.html
and a similarly designed hinge kind of like this:
http://tacomarine.com/cat--Aluminum-...alum_pins.html
Using those principles of locking and hinging, I expect your fabricating friend could make a bullet-proof folding small top for your rig. I'll try to get some pics of his on the next excursion.