Lionel 022 Switch Motors: Pre-1950 vs Post-1950

In looking at these switch motors on line, the descriptions make a distinction between the  pre vs. post 1950s switch motors, and indicate that there is some mechanical difference in the moving contact assembly between the two.

Are there any significant differences in these motor mechanics?     

Do the older ones and newer ones both work on the same switch track assemblies?

I think a distinction is that one version uses a bayonet bulb and one uses the screw bulb, but that seems insignificant.

Thanks for any info.

Mannyrock