>>1815552>I remember reading on Bob JacksonCheck it out.
If you've ever watched someone build a frame by brazing, it's likely what that site describes. "Using a jig" doesn't imply some downgrade in quality, there's nothing stopping you from doing it piecemeal, and aligning or tweaking things as you go. Compared to tig welding, the shrinkage/distortion isn't as severe, and sequencing isn't as strict.
Because you're probably interested, there are some olde Toyo videos that show a 'freehand' method:
https://www.youtube.com/watch?v=evUMrSziAkA 