Dwight and all,
Here is a link to the US Patent # 3039366 granted in 1959 and 1962 to Elmer Imthurn and Kenneth Wyatt.
Looks like one of the developers and patent-holders was a gun editor and placed the article in the "Gun" magazine to drum up interest in their venture...
On the right-side illustration view of the luger, it appears they may have been planning a cartridge-counter type "window" in the right grip panel...
http://v3.espacenet.com/pdfdoc?DB=EPODOC&IDX=US3039366