Help To Identify A Part Of This Phone

[pdxjim911]

Yesterday I met a Bell retiree, Bob, while visiting the Jefferson Barracks Telephone Museum in St. Louis. He wondered if I could help identify a part on his magneto telephone.

See this website for more info:  https://www.facebook.com/jbtelmuseum

Here is another link about the museum and contains an excellent St. Louis public radio interview with the director of the museum and her assistant.  http://news.stlpublicradio.org/post/retired-southwestern-bell-workers-unite-preserve-telephone-history-new-st-louis-museum#stream/0

The retirees have created a great museum with a working SXS display and many items of interest to those who collect.

I'm trying to identify what the function of the black ring located between the bells and the mouthpiece could be.

Thanks for your help!

Jim

[unbeldi]

Hmm, I would cautiously speculate that the top box does not belong onto the back board. I think it was a wall mounted magneto telephone by itself and the round fixture was the original mount for the transmitter.

[Jack Ryan]

I was thinking the top box may have been converted to a telephone and then returned to the backboard presumably to be restored.

Jack