Bob, so I may have solved the mystery greenport scoot ridership! Lol.
Clue: I looked at enlarged photos of the seated people in your LIRR passenger set.
they appear to be of the same generic molds of the mass produced little people that come in large numbers via Chinese manufacturing as seen on E bay. Not a bad thing if one can remove the roofs on these cars, assuming they have seats.
i recently acquired a LIRR Lionel 3 car set that only has silhouette and presume no interiors. They still look cool. No pictures today, at work. I also agree the MP 15 is a bit big by comparison. The Railking RS 3 is perfect. Also fits the color scheme of my newly acquired Lionel 027 cars.
thanks for helping solve the K line mystery.