Hot Water posted:TedW posted:Since the Milwaukee Road S3 steam locomotives have an all-weather cab design, there is a large movable & flexible/telescoping "diaphragm" arrangement between the back of the cab and the front of the tender. The piece in your photos appears to by Lionel's attempt to model that "diaphragm" arrangement.
This is one of my favorite features of the S-3. It minimizes the gap between engine and tender - much more realistic and looks great.