The Stovebolt Site Forums The Shop Area Interiors Door Glass

Here is an old post on L-O-F glass.
Their E-Z-Eye tinted glass was an option starting in 1953.

https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/998050/Glass_Date_coding.html#Post998050

I think I was told that the marking were readable from the outside (so there was right side glass and left side glass).