: You could either fillet around the edges of the mounting blocks to provide...

Actually, although I posed this question, I'm getting the feeling that my approach was a bit of overkill. Consider Dave Houser's solution of 2 2" "washers" of 1/8" lauan, no tabs on the t-nuts, and no 'glass at all. I think that I'll be a bit less excessive when I build the braces for my Coho. We're calling the Osprey "done" and hanging it in the carport until the Coho is done, then we'll pull the Osprey down and do the finishing touches (bulkheads, hatch seals, seat, deck rigging, painting, etc.).

Thanks for all of the great responses!

Later,

Tim.