When the number of subscribers increased dramatically and self-dialing was instituted, sometime before 1950, ….. (depending on where one lived that is) ….. the telephone companies had to expand the telephone numbers to seven (7) digits with the first three (3) digits being the “local” exchange #, ….. such as ….. 345-####.
But fearing that might cause problems because people were not used to remembering “7 digit” numbers they assigned 3 or 4 alphabet characters to each “number” from 2 thru 9 (which are still in use today).
And whatever the 1st two digits of the “local” exchange # was, the telephone company would choose a “name” at random for that exchange with the first two characters of that name corresponding to the # on the dial pad. I remember my parents phone # was …. Forest 4-####, ….. or, … FO4-####, ….. or 364-####
So, the phone # Valmont described as being ….. PHONE SA Ginawa 1-2444, would probably be …. Ginawa 1-2444 …… or 441-2444. The SA (72) could have been an operator # in the Chicago area.
