Stopped at Lowes. Bought plywood. 19/32" BC was the closest I could get to what the specs called for. It looked like A/C, so no complaints. I figure the extra thickness won't hurt.
Broke out the carbon paper and the plans, and started laying out the first two shapes. Got the rear seat and the rudder. The template for the rear seat was displayed 50%, and needed to be drawn one half at a time. I probably have to touch up the rudder, since the template shows a cutout for the flip-up rudder, and I haven't marked that on the plywood.
Still, it was an interesting beginning, and now that I've done it I have some observations. The carbon paper that I got from Glen-L came in a sheet 2 feet wide and 16 feet long. This is unwieldy. After trying to maneuver this around intact, I decided to cut it in half, and stored one 8 foot section back in the packaging for later use. The plan was also 8' or so long, but so far I have decided to leave it intact. When I get to the side planking, I may change my mind, but I'd hate to loose a section if I cut it up.
One final point. Now that I've got the panel for the rear seat marked on the edge of the plywood, I can begin to imagine how large this little boat will be. I know that an 8' dinghy doesn't sound that large, I can sit two people on that seat, side by side (tested with my son and I). It is conceivable that I could load 6 big guys in this little dink. (1200+ lbs shouldn't swamp it). Good to know that I can use it safely with a lesser load.
Pictures of the panel forthcoming.