Hello everyone! For a history project in my high school, I have to find an old object and guesstimate its history, origins, and how much it would be worth today. Well, I found my old object. It's my grandfather's railroad signal box phone from the 1920s. I've attached photos below. But I've been searching for more information online, and I just couldn't seem to find the specifics that I wanted to make my project outstanding. Could anyone help me identify some basic things such as model name and how much it would be worh today? And also maybe a history of how this would have been used on railroads back in the 1920s? The phone was operated from sometime in the 1920s to the 1950s, by the way. Thank you so much! I hope to get some help soon!
The phone is from Great Britain. If the plate belongs with the phone, then it is from British Railways which didn't exit until 1948, although the plate could have been changed from one of the predecessor companies.