Davis 2409.
I will bet that there aint many here that knows what that is.
No clue.
PEnnsylvania 6-5000,
BR-549
32 2409
Looks like it’s missing a number for the prefix.
You got me on that one. More than one letter in Davis should have been capitalized, though, unless it was for a 5-digit number. For example, DAvis (for a 6-digit, and so on).
The prefixes around here used to indicate what part of town that a number was from. They names standing for prefixes were used around here even after they started adding more digits. The first two letters corresponded to the numbers that the prefix stood for.

Greenfield5-2333 = 475-2333
Skyline7-9444 = 759-9444
All of Washington had the same area code, 206 until 1957 when Eastern Washington was split into 509. It was not until 1995 that they split 206 again by adding 360 for "outlying areas". Then in 1997 they split 206 again into 253 for Tacoma, and 425 for Everett and the East Side of King County. In 2017 564 was added to supplement the number pools which were again being exhausted in Western Washington can be for anyone normally in 206, 253, 360, or 425. Area codes do not mean what they used to just as prefixes no longer refer to a specific location.
I remember my dad asking for a second phone line into our house in 1972. Illinois Bell told him that no one would ever need a second line into a house. Took him months to get it done.
L
“Davis 2409.”
In Maryland I remember WArfield-7 (927) and UNion-4 (864) exchanges, but they were for 7-digit numbers.