Steve, I agree w/all here who recommend starboard or seaboard...a couple of tips for ya...WHITE only...I used light grey on my '74 and in the hot summer, you cannot stand on it barefooted...and this high density plastic EXPANDS in the summer when warm to hot...so leave some margin around the sides to compensate or you won't be able to open 'em up in summer...
It cuts easily w/a skill saw, chopsaw, jig saw and all, but doesn't leave a smooth edge w/a saw blade...if you're looking for a good finished edge, a router will do nicely...and no matter how you cut, have the shop vac handy!!...this stuff makes LOTS of shavings!!...
Good luck w/it and post us up some pics as you go...we like 'um pictures...
