David,
In 1999, the SCGA did a five-part series on the 100th Anniversary of the organization, and the first two editions chronicled 1899-1919 and 1920-1939. If you don't have those, I'll check to see if there may have been a picture of Watson. Also, have you tried the former contents of the Ralph Miller library?
The picture Tommy posted looks nothing like the picture of Watson in C&W. Am I seeing things, or is the picture in C&W not Watson?