The Railway Signal Co – Polunnio Ltd. As you can see, this is not a folding card, but only printed on one side.
Vintage General Railway Signal Company Type W Size 2, 54250 AC Relay Pat. 1953
Vtg GRS General Railway Signal Company Railroad Switch Train Relay/Type K Size 2
General Railway Signal Company Electric Interlocking Handbook (Paperback)
GRS General Railway Signal Company Railroad Switch Train Relay Type K K2
Vintage General Railway Signal Company Type W Size 2, 54250 AC Relay Pat. 1932
General Railway Signal Co Railroad Crossing Signal Reference Manual
