I have just received six bundles of 25c/50c stamps, 300 of each.
I find the following papers. The 25c recevied most use in 1943, and the 50c during the 1950s.
The Wavy Rays paper of the 1940s, the 1E3, is really a family of at least three papers:
1. Medium RA on semi-opaque paper
2. Small RA on semi-opaque paper
3. Small RA on porous paper
For now I call the medium RA the 1E3 and the small RA the 1E5, and leave for a more detailed study to flesh out these papers.