RE: Proctor Antic-Bipe build
Interesting...the Nieuport 11 uses Bamboo wingtips also - sounds like they're doing the wings like the Nieuport now.
Your rib-jig is the way to go. I originally set out to do a rib jig like yours, but settled on just pinning each half down. Either way it's far better than trying to use the multiple-pin method outlined in the book.