Update on my progress:
I managed to get the whole clutch assembly out of the transmission and completely taken apart. There are six driving discs that have clutch facing riveted to them on both sides. In my case most of the clutch facing was loose or ready to fall off, in some areas it had already escaped the disc it was attached to. After cleaning up all the parts and removing the brass rivets from the driving discs I took all six down to Long Beach CA where Friction Materials Co is located. They have been around since 1956 and like do most of the clutch relining on cars of this vintage since they still have the tools and know how. Great people, I highly recommend them if you need clutch or brake shoe relining.
After a short two weeks the driving discs were better than new. I took that time to get the rest of my clutch parts ready to assemble. The design of this multi-disc cutch has an outer spider that bolts to the flywheel and an inner spider that the driving discs are keyed to. In between each driving disc is a steel disc, called a driven disc. The Driven discs are keyed to the outer spider, there are seven of these. All thirteen discs are slid onto the inner spider and the outer spider is slid on over them. The pressure plate compresses again the outer lip of the inner spider to sandwich the discs all together to transmit power through the engine. This whole clutch assembly is then pressed onto the input shaft of the transmission. The tricky part was getting the clutch spring installed, but I have that figured out now.
I am now at the point where the clutch assembly is ready to press onto the keyed input shaft. Making good progress now. When I am all done I'll do a write up for the website so the next person servicing a clutch on their Model 14, 15, or 15B will have some instructions to follow.
https://frictionmaterialslb.com