The Elgin Calibre 722 is extremely rare, so I’m indebted to John Runciman, FNAWCC of the Chapter 50 Puget Sound, NAWCC for supplying these images and allowing me to publish them on this web site.
Information from John: “As far as I know the 722 was never sold. The only ones I’ve seen cased up are in either 14 karat gold or 18 karat gold. The 910 is an incredible mystery it only shows up in stainless cases. Up until your recent discovery, I only knew of five others. One of the others I knew of has a tag hanging from the case with the data of 12-02-63″