According to Bob Gaddis (Just re-read this) the 1st "3" Model #18's, with sawteeth were completed in late January, 1963. Gary had built the prototype a few days earlier...
Hope this helps,
Capt. Chris
_________________________
Capt.Chris Stanaback
RKCC/RKCA Founder
RKS #016
NRA Lifetime Member
CAPTSTANABACK@aol.com
WEBSITE: www.captstanaback.com