OK, so the house I live in was originally built as a Standard Oil Co. station sometime around 1920 in Green Castle, MO 63544. When we moved into the house in 1993, I discovered these cardboard licenses hanging on the wall of the original station office, stacked one over the top of the other. The outer one was too far gone to save, but the other three were in pretty great shape and I framed them to preserve them. My question is, does anyone know what this particular license was for? I have done quite a bit of searching online, but can't come up with any information about "MO. License No. 18" or what exactly it was for. I assume it was related to the gas station, my guess is it was their license to sell gasoline, but I'd just like to know if anyone knows for certain. Also, do they have any value? Thanks for the help.