Happy 46R

Looking for some expertise on my 46 Dodge D25C Club Coupe. I am in the process of replacing the clutch disc and noticed that the material at the back of the inspection cover is badly worn. My shop manual doesn't identify what the material is or a part number for it. I have checked Bernbaum and Rocket but neither show anything similar. Does anyone know what material this is or perhaps a part number for it? It looks like felt and is semi-circular and held in place by some bend over rivets. It won't hold up the return of my ride to the street but as I have everything apart now might as well replace it if I can. Thank you.

Thanks for the great information in these older posts as they are invaluable to me as a recent owner of a 46 Dodge Coupe (Canadian Model). Today I was replacing the gaskets for the water pump and thermostat housing and as my shop manual has not yet arrived I was working off of memory from when I owned one of these in 1970. Problem was trying to get the housing to sit in place with the thermostat centered as gravity would cause the thermostat to fall out of place every time I flipped the housing into place. Once I did get it in place I realized an easy solution would have been to wire the thermostat into place through the radiator hose opening. Hopefully that isn't in the manual and is a help to someone in the future. Again thanks for all the great information it really helps.

Sorry I am really late to this thread...by about 9 years but wanted to say as a newer owner and member the thread was really helpful to me while doing some work on my car. Thought I would help out by adding a picture or two showing the clip. It is basically a piece of spring steal with a hole in it folded over the shaft of the switch and anchored to the knob. The outward tension of the spring steal bites into the shaft preventing pulling the know off. By pushing gently on the outer skirt of the spring steal the tension is released and the knob comes off. Thank you for all the great information contained in this forum; lots of talented and knowledgeable folks out there.