You are correct Dave. It was the Y.C. (Young & Cadwallader) pad.
1916 H.S.B, & Co. catalog

https://photos.smugmug.com/Vintage-R...l%20Pads-M.png

H.W. Cadwallader
https://www.trapshooters.com/threads...4#post-9288322

I did find the D-W in the October 1925 Outdoor Life

https://photos.smugmug.com/Vintage-R...010-1925-S.png

I haven't been able to find who D & W were

The patent should tell us their names.

E.E. Dewhurst of Elyria, Ohio (about an hour from Goodyear in Akron) patented a rubber recoil pad #1,414,116 April 25, 1922

Good work, Drew. My SB grade single barrel had a D-W pad on it when I bought it. It was beyond repair, but I still have it. I replaced it with a Griffin and Howe Silver pad.

Orval Overall's Parker and D-W; 1932
https://sabr.org/bioproj/person/orval-overall/

https://photos.smugmug.com/Vintage-R...-%20Copy-L.jpg