William Starkweather oil and watercolor paintings

I am trying to collect William E.B. Starkweather, 1879-1969,oil or watercolor paintings and have only found one dealer, Spanierman, in New York City, who has Starkweather paintings in his gallery. Although many Museums and Universities have Starkweather paintings, where can I find a list of galleries who have Starkweather paintings?
Also, how do I get information about where all of Starkweather's paintings from his Museum in Endless Caverns have gone?

I did a little research, and came up with no new information for you about Starkweather's art work or any additional art for sale.
When I am searching for now information about a person or item I set up a "google alert".
It Monitors the Web for new content, and then emails each time something new appears.
You may already doing this. Just a thought.......
Good luck with your search, wish I could have been more help.
Maggie