20AL find

[Sargeguy]

Actually we can tell that the phone was constructed out of spare parts because of the markings on the phone.  A 20-AL was a basic all purpose phone with a 143 or 144 receiver.  The bulldog receiver came much later, after 20-ALs were replaced by the 40-AL.  If memory serves, the base patent dates are from a 20-B/20-S etc., not a 20-AL.  Furthermore we can tell that this was most likely not done by the Bell System because the 20-AL markings were usually crossed out when a phone was repurposed.

[andy1702]

London Transport used to do this sort of thing for their internal phone system. They would buy whatever equipment they could cheap and then cobble together something that did what they wanted out of the bits they had.

[Pourme]

It's like having a family dog that was a mix of whatever dogs live in the neighborhood, but you still accepted it into your home.