custom fabbed tonneau's

[chevy72blu]

How many of you guys have custom fabbed your own tonneau covers? Ive been thinking about using sheet metal and welding in tabs/supports to drop in flush with the bed rails all the way around. It would add a little weight in the ass in addition to covering the bottle and fuel cell (Ill most likely mount one in the bed until I get around to putting it under). I googled around and couldnt find much besides people making them out of plywood.