You have to look down to the ground and inside doorways to find them, but references to New York’s old two-letter telephone prefix system still exist.
These signs are probably at least 50 years old, as the two-letter exchanges were phased out in the 1960s.
EXeter 2 existed in Queens, hence this sign on West 19th Street for the Marcato Elevator Company in Long Island City.
Kaufman Management Company still has its offices at 450 Seventh Avenue in Midtown. They no longer use the LOngacre exchange on signs or in advertising, but they could: their current phone number is the same as it is on this 19th Street plate.
This website is a great resource for looking up the history of the city’s old exhanges.