Fitting and assembling the top:
With the carcass on its side still, place a piece of bending plywood, again starting at the rear where the curve is tighter. Allow a bit of overhang that will be trimmed later, and clamp the end of the ply to the rear brace. It's good to use C clamps here - the ply will be under some pressure and the end needs to be very secure when glued. You can use a backing strip of wood to help. Spring clamps are appropriate for the rest of the perimeter. Carefully bend the ply around the form as tightly as you can and mark the other end, again allowing some extra which will be trimmed later. Remove and cut the end you marked. Now for a dry run. Again clamp the rear end to the brace, bend the ply around tightly and clamp it to the front brace. Use just a few clamps of the spring variety in front because we are going to snug the ply more tightly with strap clamps and so the clamps now are just to hold the ply in rough position and will be loosened to allow movement as the straps are tightened.
Place three strap clamps (cargo ratchet tie downs) around the ply starting at the top. Hook the ends together to make a loop, with the hooks and ratchet in the space where the bottom will go and snug it down - just snug, don't crank, yet. Place the top strap and snug, then one in the middle. Check inside to see that the ply is pulled up tight to the form all around as you tighten the clamps. You'll have to place the clamps that hold the end to the braces leaving space for the straps. Crank the straps and recheck the fit inside. When you're satisfied, remove everything, place within easy reach, run a bead of glue around the kerfing, both sides. Too much and it will start to drip all over everything. You want enough for a good joint but not an excess. You can't do this gradually, a foot at a time like the kerfing because you're doing both sides at once. Be quick! Get the kerfing glue applied, then run glue along the rear brace - be more liberal here, as it will be under more pressure. Slap the ply on, clamp the end with a few to three clamps and get to bending around while that glue is displaying its obedience to the law of gravity. Glue up the other brace, throw on a clamp or two to hold it temporarily, get those straps in place! Don't get right next to the edge of the ply or you'll glue the straps in place too - allow ½ inch or so from the inside edge. Snug the straps - you'll have to release the clamps on the front once the straps start holding the ply to allow it to move as you crank the ratchets down (don't test the breaking strength of everything, but crank it down and check inside to see that the ply is seated to the kerfing all the way around, especially along the flatter top section). Now go back and add C clamps to those ends, at the outermost edge of the braces, where the pressure will be greatest. Check to see that the ply is seated completely at both ends. Now relax, breathe, the excitement is over - until the next layer of ply. Let this set up overnight.
In the morning, remove the straps and clamps, clean the joint between the side and top with a scraper. You can trim the ply overhanging at the braces with a mat knife, making repeated light to medium cuts against the brace as a guide until you cut through. You may want to support the edge as you do this so you don't pull the ply loose at the edge as you cut with the mat knife, just don't support it with a slashable body part like a finger. Clean the face of the braces with the scraper. Test fit the second layer of ply to see that it'll go around without binding. If it does bind, check for glue on the inside of the side you may have missed. As a last resort, sand the edge of the ply where it's sticking. Clamp the rear end in place, bend around to the front and mark the length, allowing some extra to trim later. It will be a bit longer than the first, because of geometry involving circles and pies. Remove and trim the front end to the newly marked line.