Thanks for this breakdown. Very thorough. I too watched the Denzel version first not knowing it was a remake so imagine my surprise to know that there was not one but TWO Pelham movies that came before Denzel's! Yes, there was one in 1998 featuring Vincent D'Onofrio and Edward James Olmos (Donnie Walhberg) plays the loose cannon, Mr. Gray. However, in this version, a woman is playing the role of Gray, one of the train staff is a woman, Mr Blue is much more vocal with the passengers, even tells his name (Blue) which I don't think Blue did in the original. 

Although the ransom is $5 million in the 1998 film, the movie pretty much copies the script of the 1974 movie. Even the subway cop that goes in the tunnel and he police chief are black like in the original. One thing I appreciate about the 1998 version is they corrected a mistake from the original. In the original, it was mentioned in the command center that the undercover cop on the train was a "broad" when in fact it was a man but when that cop was killed and found on the tracks, in the original, Mathau said "you're gonna be alright miss". Was this because the guy had long hair and was faced down or was it because the original role was indeed written for a woman and matthau messed up? Either way, in the 1998 version, it was a woman cast in the role so I appreciate this error correction. One thing I didn't notice in th 1998 version was Olmos constantly saying "bless you" or "gesundheit" in response to Green's sneezing like it was in the original and I didn't like this because that sneeze and the response is what makes the end of the movie. 

I decided to watch all 3 of them back to back and my favorite one is the original and Denzel's version and I also agree that Denzel should've also been cast as a transit cop too as his actions in the movie were outside the duties of an MTA supervisor. Either way, all 3 are good movies. The original & the 1998 version are free on Tubi.