Two locations, according to the back of the card; both in Times Square. When they first opened, the clientele was probably still decent enough - folks heading to a movie, or coming back from the same, or someone getting a bite before the train. Self-service. A glorified cafeteria.
You can only imagine how must have looked, and smelled, in the years of Times Square's decline.
This page says there were four Hectors, and one of them appeared in the opening pages of Kerouac's "On the Road." Beats apparently loved the place. This page says the first pedestrian crossing lights were erected outside Hector's. No doubt the Beats found them symbolic of the many injustices of an oppressive society. Don't walk, man? Now we got machines telling us we can't walk?