Nobody Likes A Trick Chair!

I have a client that has a set of 10 dining room chairs that are "Trick Chairs". What would be worse than having a dinner party and have a guest scoot there chair closer to the table and fall through the chair frame because the cushion has dropped through the frame. That is the "Trick" with these chairs. The first picture shows what happens to the cushion. The problem is that the chairs lack support for the cushion at the rear of the frame allowing the cushion and the guest to fall through. The first step was to make templates of the rear frame, so I could determine the angles to cut the support pieces. The second step was to cut the support pieces from 1" x 1" hardwood stock. The final step was to glue & nail the pieces with 1" Crown Staples across each of the rear frame corners.