Built it to open in middle, easy access from both sides and both ends. 3/4 inch sandply plywood, routered the edgees, painted it afterwards and wrapped it with military vinyl. Used carriage bolts so could not be taken apart from outside, now will concentrate on locking mechanism. RTT is going to be on a telescoping rollbar roofrack type system. WIll be working on that in next couple of weeks. Middle support is pressure treated 2 x 4. WIll also be installing a rubber weatherstripping around top edge under lid and a strip of the vinyl will go over the middle support to cover gap and hinges. Cheap top for around $150, all quotes for the metal top I was wanting was around $500, so this will do for now.
R
R