B & O Railroad Material Cards Qty 5 Baltimore and Ohio Train Collectible 1950s

Five material cards (Form 2311-Rev) from the B&O Railroad (Baltimore & Ohio). Each card measures approximately 8.25" x 3.5". There is no writing on the front of any of the cards. On the back of each card are a series of numbers and letters written along with a date at the bottom. All the dates are from the 1950s. Some minor wear along the edges and corners. See pictures for further details on condition.