The Calfee jig puts the frame centerline at 101 mm in the air... or four inches. I stopped by the home improvement store with the kit's hardware in my pocket. I started in the tools, but their selection of rasps was pretty crappy, so then I went over to the plumbing section.
The bottom bracket shell sits over the outer diameter of a threaded 3/4" fitting and the fitting has a hex that the shell will rest on. I had a hard time doing math while wrestling the 2yo, however, and so I didn't get it up to exactly the right altitude, need to go back and get a different stackup.
The seat post shell fits over a 3/4" pipe nicely (3/4" pipe is 1.05 inches, 27.2 mm seat post is 1.07 inches).
I was looking for a similar trick with the head tube... But I stopped there since kiddo was bored with playing with pipe fittings and needed lunch and nap. The seat tube and BB shell will get me through first blood on the bamboo. I looked it up just now and the OD of a threaded 1-1/2 PVC fitting should be 1.72, which should do the trick.
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Genesis 49:16-17