I have had this TYDOL price box for over 25 years but have never seen another like it. It is two sided and I believe the lower levers once flipped the internal metal price signs for displaying the current gas price. I assume this likely hung in a gas station window or maybe under a protective overhang. The sign measures 13x9x1/2 and is heavier than it looks due to the internal metal price plates. Can anyone shed any light on this item?