Can anyone tell me what these initials stand for, they are on my grandfather's Altoona PRR work record from the railroad retirement board. Are these locations in the Juniata Shops or Altoona? Thanks in advance, Dale Patterson Year: 1910 Occupation: Messanger Department: G.S. (E. F.) & G.S. M.P. Location: General Office Year: 1917 Occupation: Car Repairman Department: M.E. Location: A.C. Shop