My family has lived in New York City since it became Greater New York. Before that, we lived in the City of Brooklyn. I'm going to be 59 this year. So, I'll say this will no concern that you'll disagree, because... if you do, you are wrong. There are multiple accents here, divided by class and ethnic group, and each speaks somewhat differently. Wall Streeters speak differently than Cabbies. There is a distinctive (and IMHO, very lovely) New York African-American accent. It's a mixture of New York and Black and It's one of the nicest in the City. I'm not sure I've ever heard it on TV, though, except in local news coverage. I hear it a lot as I shop in Harlem and it is also spoken in parts of Brooklyn. The old Tirdy-tird accent... I don't hear that nowadays, except in the old movies and on some West-coast based TV shows. I don't recall hearing it in my youth, either. As a child I asked my parents why on TV New Yorkers talked so funny, and they said people did speak that way in the late 1920s and early 1930s. Of course, you'll say my parents were wrong, and my childhood ear, growing up in the 1950s, was wrong. It could be that in those days it still existed around the dockworkers, but it was no longer common in the ordinary blue-collar neighborhood of my early years. There is still a blue-collar accent, but it's slightly different.
Graffitti likewise was washed from NYC subway cars by 1980, but continued to appear on them on TV for decades after that.
Fortunately, NY has adopted a pro-film pro-TV policy and most shows set here are now shot here, so that type of error is less common.
In fact, Marvel/Disney has just announced some web series that will be shot here.
I suspect in 1964 NYC, an ad man would not have said, "you oughta" that's very blue collar. He probably would have said, "you should."