Here's some Guild 12 spec. info from another thread........
Dreads: D & G
D-4-12: Sitka spruce top, mahogany back, sides & neck, satin finish
12 string version of the D4
D15-12: All mahogany top (satin finish), back (arched) & sides
Early/mid 80's release, based on D15
D212: Spruce top, mahogany back/sides, mahogany (laminated) neck
The D212 (at times refered to as D25-12) was pretty much built at the standards of the D25 and had (or had at certain times) Engelmann tops.
D212-M: Spruce top (stained dark), mahogany back/sides, mahogany (laminated) neck
D25-12: Spruce top, mahogany back/sides
D412: Sitka spruce top, mahogany sides, arched mahogany back, mahogany (laminated) neck
The D412 (at times D40-12) had Sitka tops and should have the slightly fancier D40 features, upgraded rosette and added purfling. Back was arched or flat depending on year. Gained thickness of the top somewhere in the late '70s.
G212: Spruce top, mahogany back/sides
The G212 was based on the D40. Also came in a cutaway model.
G312: Sitka spruce top, rosewood back/sides, mahogany (laminated) neck
12 string version of the D50
JF Series
JF4-12: Spruce top, mahogany back and sides
JF30-12: Spruce top, flamed maple back/sides
JF55-12: Spruce top, rosewood back/sides
JF65-12: Spruce top, flamed maple back/sides
JF100-12: Spruce top, rosewood back and sides, maple binding
JF100-C-12: As above with hand-carved heel
F Series
F112: Spruce top, mahogany back/sides, tortoise or black body binding; 19.25 L, 15.25 W, 4.5 D
F212: Spruce top, mahogany back/sides, white body binding; 20 L, 15.875 W, 5 D
F212XL: Spruce top, mahogany back/sides; 21 L, 17 W, 5 D (this is the only mahogany model in this size)
F212XL is wider and deeper than the F212...also has nicer woods and Chesterfield logo
F312: Spruce top, rosewood back/sides; 21 L, 17 W, 5 D
F412: Spruce top, flamed maple back/sides; 21 L, 17 W, 5 D
F512: Spruce top, rosewood back/sides; 21 L, 17 W, 5 D
F612: Spruce top, rosewood back/sides; 21 L, 18 W, 5.25 D
18" lower bout