The old 1.5 tonner I rode in had a sheet of painted plywood across the front of the bed, with a hole about 16"x24" covered with hail screen as a center window. Are you going to have some kind of additional structure across the front to support the canvas?

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Water separates the people of the world; wine unites them.

"If you have good manners and are well spoken, you can be welcome anywhere." -Mom, 1959