AirBox is a bigger job than I imagined... I logged about 12 hours over the last 2 days.
Fabricated the carb heat door, cut the airbox to shape. Installed the hinge / hinge arm. Installed the carb heat cable, cut to length, and tested operation. Installed the carb heat intake to crossover exhaust, and mounted the heat intake tube to airbox. I need to get some 2" scat tubing to complete the assembly.
Cut the bottom of the air box for the alternate air intake, drilled / sealed and mounted the flange. Fit the alt air door, installed the control cable in the cockpit, and cut to length.