As reported by Mike Gretz in another thread somewhere, I forget now but:
The original Van Loo Chipmunk from 1967 was 57" Span
The Mike Stott Chipmunk was 55 1/2"
The Sig Original Kit was 54"
The Sig Super Chipmunk kit is 54 3/8"
Here is the kicker, every one of them used the exact same root and tip rib templates!
Jim Pollock