prewar cardboard coupler rings

[cbtrainman]

Hi my fellow collectors -

I recently acquired a small collection of prewar Lionel rolling stock.  The neat thing is that the original boxes were present, and in really nice shape,  some even with inserts.  There were also several heavy cardboard rings or cylinders, approximately  1 1/2" in diameter and 1-1/2" long.   Do you know if these might have been part of the packaging - a way to keep the boxes from being damaged by the couplers on the cars?

I know that Lionel did provide this type of ring to protect some postwar alcos, but, didn't know if they did this in any prewar stock.

Thanks for your input!  and,  my best wishes that your Easter was meaningful this day.