Details: Furniture Store Auditorium

In celebration of National Architecture Week, I'm sharing a series of posts about architectural details in historic and charming downtown Grass Valley, CA.
The first detail I want to share is something it took me nine years of living here to notice, a set of window-like plaques on the second story of a furniture store. 

The plaques read "Erected anno domini MDCCCC Grass Valley Auditorium K.P. N.S.G.W. I.O.R.M. G.V.M.V. A.O.F." After some internet research, I discovered that "anno domini MDCCCC" means AD 1900, N.S.G.W. is the Native Sons of the Golden West and I.O.R.M. is the Improved Order of Red Men. So this just begs the question, what was this building originally? A public auditorium with dances and basketball games? And how did it turn into a furniture store?