My Grandpa's Collar Container

I never got the chance to meet my Grandpa. He died, suddenly, of a heart attack in his early fifties.
He was a keen photographer and I have a box of his glass slides from the 20s, a photo album, as well as his wonderful Kodak camera (circa 1901).
This leather (not box) but circular container was where he stored his collars. The photos I have of him show that these stiff collars were bloody uncomfortable, but that's what was the fashion in the 20s