The stand is finally done, and the jig is mounted. All I need now is a centering cone for the seat tube and the jig will be complete!
I'm thinking about getting some cheap 4130 steel to do a practice run... build up a "rough draft" frame, so to speak. At the very least I'll likely use the jig to tack a few joints, then fillet braze, file and finish them. It's tough to decide whether I should just jump right in and start making my first frame, or if I should practice some more. The seat tube cone is probably a couple weeks out, so I have some time.
Other than brazing practicing, the wait will give me time to sketch some designs of the custom fat bike, finalize the geometry, and ultimately produce up a life-size drawing of the frame. I hope to be buying frame tubes in May, and brazing my first frame in June.