I am, by no means, the final authority on Old Yeller, but all research and conversations I have done and had with quite a few different sources have concurred that the shop-supplied Westinghouse Ivorite was all paper. All examples posted within this thread and subject certainly look 100% shop made.
Just sayin, Capt. Chris
PS: I have not researched the white lineal but it looks (to me anyway) to "not" be paper, i.e. linen.