This part of the famous film (02:04:50) should happen in 1966. All cars, buses, people dresses look authentic except of this lantern.
Am I right the fixture isn't so old but from 1990's when it was filmed?
Yeah, they underestimated lighting enthusiasts. A few seconds before that there's shown full street of them. Changing all of them would mean extra expenses and time, so they probably didn't bother as they are quite far and out-of-focus.
Flat LED streetlights in such situation would be a bigger mistake though.
The film people probably don't even know that about the lights. This is common in a lot of movies. The light is an American Electric 125 and could have been installed anywhere from the mid-late 80s to the time the movie was filmed.
Flat LED streetlights in such situation would be a bigger mistake though.