METAL STEM & Plug in bowls
The Modern Pipe Company of Mt.Morris, Michigan manfuactured the Vance around 1947
The aluminium pipe with a briar bowl has a collapsible stem. A metal cap is placed over the collapsed stem for carrying in the pocket and keeping the bit sanitary and clean at all times.
Intake holes in the metal shank are placed at the halfway point,so that only smoke goes through them, all tars and gunk dropping down to the bottom of the metal base.
Not having an example I have to surmise that the bowl is a push fit, but this will be amended whenever an example comes to light