I am working on the body of my 15 touring. The front seat heel panel and the front seat seat back were not attached to the body when I bought it. What type and size of fasteners were used to attach these parts to the body wood?
The heel panel is retained by three fasteners, arranged vertically. The uppermost is a 1/4" carriage bolt with its head countersunk in the wooden pillar and of suffient length to pass through this pillar along with the panel and take a square nut with a lockwasher on the end. The center and bottom fasteners are #10 or #12 round head wood screws.
The seat back uses three round head wood screws on the bottom edge's vertical 'lips', one on each side, that fasten to the inboard surfaces of the pillars and are retained by a flat strip of wood. The armrest sections are also retained by wood screws. Some bodies also may have had Z-shaped metal strips that aligned the ends of the upholstery tack strips and retained the ends of the seat back panel side "arms."
I agree with R.V. except on terminology of one fastener. The bolt that is visible from the outside of the car is a step-bolt and it has a larger diameter head than a carriage bolt. Many fastener houses carry them as do Lang's.
I find step bolts in most of the hardware stores. If you look on the side of the T in the picture you will see original step bolts. Like it says above the heads are larger.
I'm on the last leg of turning this back into a car