I found this. I don't know how up to date it is.

Flycraft
PO Box 60582, Greendale Station, Worcester, MA 01606
(50 853-3676 FAX: 3676
Contact: Randy Swanberg
E-mail: randy11@ix.netcom.comThe Golden Mean Proportion Tool is the only fly tying proportion tool based on the formula that natures uses to proportion many lifeforms, from insects to human beings, including mayflies, stoneflies and caddisflies.