Unusual Plug on AE40

[LM Ericsson]

Hi all,

I recently received this nice AE40 with chrome trim in the mail equipped with an unusual five-prong plug. Was this phone used on a special phone system? Thanks

[Kellogg Kitt]

What you have there is a Jones connector.  I found one, along with its wall plate on a Kellogg MK500 set.  I posted some pictures of it here:

https://www.classicrotaryphones.com/forum/index.php?topic=24977 (message # 19)

There are other interesting connectors and some other Jones connectors in that thread, too.  Interesting reading.