I am not aware of any, but you may be able to adapt these if you're willing to cut the plugs off (you don't need the white wire in the Lionel "plug n' play").
If you're just looking to power the Lionel "plug n' play" flagpole without having to use the plug, you can just cut it off; tie back the white wire; connect the red and black wires to one side of the below adapter; and then connect the other side to a power source like an accessory port of a transformer with the proper voltage.