The issue with my interest in H. H. Dean from the information posted by the O.P. is basically because it is my hometown. I asked a few of my "older" friends about the address location which in my time was used as a nursing home and most recently a drug rehab type of establishment. None of them can remember a "gun store" that they would visit. I did a little local research and came up with Mr. Dean's involvement with the Great Northern RR from construction through the Cascade Mountains and later as an engineer retiring in 1939, he also owned the H.H. Dean Motor Company from 1910-20. There is also a vault with some of his photographic interests, which combined with interest in hunting and fishing in his later years led me to believe this was the guy that owned the storefront and ordered the revolver. No other Harry H. Dean and son Dodge come up in local history. I'm still poking around, more old buddies to ask.