You can see that I moved on to cutting the mouth directly from pipe. That also gives me the ability to move the upper lip around and optimize its placement.
Also note the use of PVC pipe fittings. Put them on the same place on each pipe, and you get not only a cool design motif, but interchangeable parts!
And a ten-foot, 3" pipe (ooh)...
A closeup, featuring the Fasco blower I recently bought:
The wooden box is a fixture my brother and I put together to test multiple pipes.
Note that the upper lip is still cardboard. We tried sanding a thin wood piece to a fine edge, but the cardboard still seemed to produce the nicer tone.
That graph (nomogram, I guess) on the floor solves the Ising equation relating several design parameters of an organ pipe.