METAL STEM & Screw thro bowl
Alcoa were casting or extruding aluminum tubes used by several pipe companies:
Alcoa (Aluminum Company of America) cast pipe bodies certainly those used by Comet.
"The body of the pipe can be hexagonal, square ( Thoro Kleen only seen this shape) or circular in cross section. Regardless of the shape, all parts are interchangeable. The tube bodies by Alcoa were used by "Knowles Air Lite (believed to be Canadian version), Roybrooke, Comet, Original Gridiron and the Greenwich House Thorokleen." And all the bits were coming from a same supplier as well, there seems to be a selection of mouthpieces, some taking a filter. All come initially from the Greenwich House Corp, New York.
With the briar bowls coming from Kaywoodie it made for quick assembly.