George Gruhn was at Guild from 1984 to 1988. Kim Walker was there from 1986 to 1994 as far as I was able to find.
Gruhns's Guide to Vintage Guitars, 3rd edition page 395:
"
In 1984 Gruhn designed a new group of models...introduced the narrower "snakehead" peghad...Dreadnought styles were numbered in the 60s, F-style...were numbered in the 40s."
F-42/D-62 mahogany
F-44/D-64 maple
F-46/D-66 rosewood
So he only mentiones those 6 models as "his design".
Also the following were designed when Gruhn was there:
Nightbird
Nightingale
Studio 24/S-60 Studio
I don't know which models Kim Walker started to design or co-design, but the whole GF series was also designed when Gruhn was there, however he does not claim the design in his book. I actually think they only came out when he just left.
GF-25/GF-25C mahogany
GF-30/GF-30C maple
GF-40 mahogany
GF-45CE (renamed F-45CE with snakehead, not sure if hog or maple)
GF-60R/GF-60M
So I think some are "designed by", some "co-designed with", still waiting for Hans' second book...
Some info about Kim Walker here:
http://www.letstalkguild.com/ltg/sh...esident-of-Guild-1986-1991-The-KIM-WALKER-ERA!!
Ralf