Fellow Gibson historian Paul Fox recently unearthed some important rare documents: 2 issues of The Sounding Board. This was an in-house magazine (later more appropriately called The Sounding Board Salesman) published mainly for the army of Gibson teacher/agents, who were out making Gibsons the most popular instruments of their day. One is the very first issue! See more info on Paul’s site here. A big thanks to Paul (and his source, Scott Kern), who has generously scanned all the harp guitar material for our site.
There doesn’t appear to be any new critical harp guitar history in these issues, but of course, plenty of advertising and promotion.
Volume 3, No. 3 from 1914 includes this wacky harp guitar plug:
Best of all is the photo of a quintet made up of key Gibson personnel, including General Manager Sylvo Reams on mando-bass, and – clearly the “alpha male” in the group – Sales Manager Lew Williams on mando-cello.