I'm afraid it was in the early 60s, when my teacher played the instrument. Ironically, we moved back to Toms River, N. J. and I had a new organ teacher. She also was a Wanamaker organist and her husband was one of the original builders on the instrument. Her name was Alma Becker. I forget his first name, after all these years. The original organ was featured at one of the world fairs, maybe the St. Louis World's Fair, and then disassembled and shipped by train to Wanamaker's. Once acquired by John Wanamaker, it was greatly expanded into one of the largest organs in the world, at least at that time. I remember her husband telling me that they made their own fish glue, to glue the wood pipes together.
Wow, you're not going to believe this. When I was a kid, back in the early 60s, my organ teacher was Leonard McLean, and I took my organ lesson at his studio in Philadelphia. We lived in Cherry Hill N. J. at the time. He was one of the Wanamaker organists, so when he played the big organ, he'd take me with him. So I got to sit right next to him and watch him. He was one of the great theater organists of his time. His stage name was Melody Mac. I'm sure he'd come up on Google. Anyway, one of the things he taught me was that the organ was so big, you didn't change sounds by putting down one stop at a time, but rather, you'd swipe several at once or a whole bank of them.