It's fairly common to find ancient store signs in New York City that feature the old-style phone numbers, with the two-letter exchange preceding the five-digit number. To see such a phone number in neon—as is the case with this small liquor store on upper Broadway—is more unusual.
The TR exchange stood for Trafalgar, I believe. It's a pretty solid phone number, easy to remember. Perhaps that's why the shop has kept it. Or maybe they saw no need to replace a perfectly functioning neon sign.