Another hour in the shop. Attached more 1/4" plexi blocks to the rib jig so it holds all the pieces of 5/16" square spruce, but it may need a couple more for more security. Finally popped open the box of spruce from Wicks and pulled out some 5/16" square sticks to check the fit of the jig. After getting all the blocks placed, I cut pieces to fit and loaded up the jig.
