I am in some confusion over this telephone. The markings inside the case are thus:
GPO TE33 No.3238
These markings indicate a General Post Office Telephone No.3, made by the Telephone Manufacturing Company in 1933 (Manufacturers Code 'TE', year 1933). The '238' is possibly it's mark number. I cannot find any reference to a Telephone No.3, but I do have 'N' diagrams for a Telephone No.11 (with a line Drawing that depicts my example here, but fitted with a writing tray. You can see the plugs where the tray has been removed from mine). The date on this diagram is 1917, with amendments in 1938 and 1957. So, if someone could enlighten me I would be grateful. This telephone was working on the same Private Manual Branch Exchange (PMBX) as my Telephone No.251LB. They were both still in limited use in 1982.
