I was just reading about the colour last night (Fender - The Golden Age - 1946-1970) It was a CBS marketing decision stemming from on the Coronado guitars binding. While using a heat-gun to soften & bend the binding material, the wood was scorched in places adjacent to the binding. Probably because they were somewhat inexperienced and/or rushing to crank them out. Fender hadn't done binding much until the later 60's when CBS took over. 'Grayburst' as they called it originally was devised to cover up the burn marks. A pic in that book of a Coronado II guitar (page 234) shows an 'aged' Antiqua model that looks awesome - the rich almost tobacco/pale green colours on that example really work for me. I've not seen one that looks exactly like that - especially the recent re-issue which reflected the late 70's version which is more silver-grey.