Jim and forum members,
Hello, long time reader and first time poster.
Your letter openers are pre-war and war-time era produced, made for promotional trinkets as well as used in house. This validation comes from Max Hayward(?)...look in your War Baby books. Max was the engineer that worked at Inland and provided Larry Ruth with his info. All pics in the Inland section will say "courtesy of Max Hayward".
Inland made these in a variaty of colors, I have one in yellow, it came from the Engineering bldg. 13. The opener you show, with the tab on the bottom, is actually a casting sprue that has not been ground off.