Here is a nice steel Adlake Switch Lock (no key) from the PC (Penn Central) Railroad. "PC76"" is stamped in the main body, non-keyhole side, of the lock. The numeral "76" is also stamped on one of the rivets on this side of the padlock; either it is terribly patriotic or stands for the year the lock was put into service (1976)- I suspect the latter. On the other side of the lock, the drop (moveable cover piece for the keyhole) has the manufacturer's name ADLOCK in bold raised letters. There is no other lettering on the lock body except for a small trapezoid with the letter "B" inside stamped almost illegibly into the shackle.
CONDITION: The lock is typical 3-1/2" high. NO KEY. The drop still has strong spring action. The lock body has very little evidence of rust. The shackle has a somewhat rough surface from past rust, though no red rust remains- it may have been cleaned in the past.