Hi Bob,
I don't think there will be any clearance issues with the plates as they are above the wood,(when the roof is inverted), and out of the way of the front angle iron piece that attaches it to the windshield frame... will find out for sure soon...
Hadn't even thought about strenghtening the rear upper pieces.
edit: After looking again at the clearances above the wood structure, it would be possible to add a continuous bracket around the entire roof wood if someone really wanted to stiffen it up...
I do figure that with about two dozen or-so bolts to line up perfectly to get this roof installed, I better leave a little wiggle-room somewhere, or I will have a fight on my hands.....
Thanks, David