Binoculars Nash Calvinator Corp 1943 HMR M3 6x30 with leather case M1

Binoculars are in good used shape. There is a “ranging line” inside that looks like a backwards “L” with a slight extension on the bottom right horizontal line and also a vertical extension past horizontal. The bottom horizontal line reads “5” to “5” on each end. The vertical line reads “5” at the top and below the horizontal line is a “20”.