Odds are it was put it the trash decades ago. That is the Irvona br on the left. I can not figure what zone B is as it couldn't possibly be the Alleg B division as it didn't come down that far,especially towards Cresson. Could have been a split for transportation designating M/L from Branch lines for operating purposes.
There were other signs that were made to show the dividing lines for divisions. One was at MP113.4 just west of Banks. The old C.I.marker was there plus a wooden sign for the Allegheny Division,although not similar to the Cresson photo marker.