The O'Jays "Love Train" Music video (Found Music Video, circa 1973)

In 1972, The O'Jays released their hit song Love Train. A music video was recorded one year later in 1973. The music video is considered lost, as there are no videos of it on YouTube. (There are videos of The O'Jays performing it live, but those have nothing to do with the music video itself.)

Summary
According to Wikipedia, the music video shows a group of people forming a chain near a railroad station, while at the same time, some railroad cars are shown in motion.

Throughout the video, more people join the chain, which they call the "Love Train".

More info
It was most likely filmed around the Northeast Corridor, as Long Island Rail Road MP75 cars appear throughout. (in which the words "LONG ISLAND" can be seen), as well at Amtrak cars and other rail cars. Not much else is known about it, other than the fact it was recorded in 1973.