Repair:
First I removed this screw, dipped it in some wood filler, and screwed it back into the wall. With the back panel removed, the dinette frame can be shifted easily until it's flush with the wall.
There are two long screws securing the 3/4" x 3/4" beam to the floor. They were removed and reinserted into the floor slightly so they wouldn't be lost. Once I cut a new 3/4" board (picked up at Home Depot), I placed the old and new board side by side. I inserted two, small nails into the screw holes of the old board to mark the angle of each hole. I dropped bown to eye level and with a small drill bit, I drilled two pilot holes into the new board to match the angle. This allowed me to insert the same screws into the same holes exactly.
I ended up using one of these corner backets (Home Depot). You'll see where in another photo.
I did not disassemble the frame where the booth door is. I pulled the pieces apart far enough to reach in with a dremel and cut the staple flush. Staples typically will prevent you from joining wood as they never seem to go in the way they came out. Staples have to be removed or cut for a good seal.
After cutting the staples, I clamped the frame of the door to the booth frame.
Clamp job from the top.
With the leftover 3/4" wood I had remaining from the floor piece, I cut and placed a center beam to help with weight distribution. Totally optional.