I put the dark green 9 loco into running order and decided to do the cars. They have added lights that appear to be from a kit:
I took the one out of the first car because I always put the trains back to stock, but when I saw the construction I realized this may be a kit by a company other than Lionel. The light head has a slot and a tab that were used to tie it to the crossbar in the cars.
Here's the contact end- a cotter pin on an end of the wire with the insulation bound on the end:
The set is two lights on a long wire. One set has been cut in half to make two lights - one for the combine and one for the observation.
This set of trains was made in 1929. I got it from the original owner's son along with the son's 1952-54 era O gauge trains I doubt the trains were ever set up and run after the mid-1950s.
Have you ever seen a set like this?