Hi Matthro, welcome aboard! I waited for a while to see if this would be answered, I think you meant "from when to when?"
A brief history from
here :
"The first Guild 12's were the F212 (16" lower bout) and F312 ca late '64-'65. Those early models frequently featured extra-wide (nearly 2") nut widths and flat radius boards. Ralf Towner was a fan of that variant.
Next up in '68 was F412 based on the F50 (arched maple backs 17" lower bout). The F412 begat the very earliest F512's as "F412 Specials", which, as far as I can tell, were built "just to try it". IIRC early F412's/512's were special order only, and that being the case, easily tailored to a customer's special requests (within taste and reason.)"
What I left out there (due to tunnel-vision regarding
"custom" 12's) was that the F-112, based on the F30 body specs, was introduced in '66 according to the Guild Guitar Book, our forum "bible" for Guild History from '53-'77. It was still in production in '77, but don't recall when it was discontinued, think by early '80's at least.
The F212/312 were based on the F47 body specs. The F312 was discontinued in '74 and but don't recall when it was discontinued.
Personal opinion, the 16" lower bout F-body is the sweet spot for Guild 12-ers. Perfect balance of sound output and playing comfort.
Guildedagain's observations on his F112 get my curiosity up, though. The 112 was nominally 15" wide lower bout.
For reasons unfathomable to me Guild abandoned the 16" lower bout F-body platform after relocating to Oxnard in 2105. (I'm gonna leave that typo in as a sly reference to Guild's multiple relocations over the last 25 years. but meant "2015"
) To be fair 16" lower bout 12's were gone by '87, long before close of Westerly in '01.
Possibly not-so-coincidentally, this occurred under George Gruhn's part-owner/management of the company. Gruhn introduced a new mode prefix for the 17" lower bout F-bodies, the "JF" series. This led to the JF65-12 (formerly F412), the JF55-12 (formerly F512), and the JF30-12, a "workingman's" F412, and with a string (strong
) following here.
I suspect Gruhn had plans for a 16" lower bout F-body 12, as he came to Guild to update the basic 16" F body and dreadnought platforms in '84. The 16"lower bout
6-
string F body remained in the line continuously from inception ('54) until the Day of the Cordoba. (Oxnard).
So suspect Gruhn simply updated the 17"-ers first.
The F412 and 512 were 17" lower bout F-body and have been in the line under one name or another virtually continuously since introduction, with notable spec changes to the necks in Tacoma in '07, from Guild's classic and one-of-a-kind dual truss rod design to a single truss, reinforced with carbon fiber flanking rods. Allows a slightly thinner and lighter neck.
Absolutely.