1970s Conn F-100 000-Size Flattop Guitar
This is a consignor's all-ply, Japanese-made, x-braced "campfire guitar." It's well-made and lightweight along the lines of a same-period Yamaha, though it has a little more midrange grunt and a slightly looser high-end.
I'm always impressed by the economy of means in these factory-built Japanese guitars of the time -- the bodies have quite thin 3-ply all over, though the design takes advantage of the ply's resistance to the elements by lightening-up the bracing. This gives them a full, round, warm tone despite not having fancy materials. They're also stable, too.
Anyhow, previous work (by someone else) on this looks like a neck reset and possibly bridge reglue, as it had a good neck angle and decent compensated saddle on it when it came in. My work included a fret level/dress, some fussing with the tuner mountings, and a good setup. It plays well with 3/32" EA and 1/16" DGBE action at the 12th fret and it's strung with 12s. The neck is essentially straight, but the treble side has more relief (hair over 1/64" deflection) than the rest of the neck when dialed "flat" at the truss-rod.
Specs are: 25 3/8" scale, 15 3/8" lower bout, 11 3/8" upper bout, 4 1/8" side depth at the endblock, 1 11/16" nut width, 1 1/2" string spacing at the nut, 2" spacing at the bridge, a 12" radius to the fretboard, and a mild-to-medium, soft C/V neck shape that's actually a lot like a same-period Yamaha, too.
Woods are: ply spruce top, ply nato(?) back/sides, mahogany (or nato?) neck, rosewood fretboard and bridge. The instrument appears entirely original save perhaps the saddle.
Comments
FYI, the neck joint on mine (and maybe yours) is a sliding vertical dovetail that's set in with some epoxy. I needed to adjust the neck angle, I loosened the interior neck bolt, freed the fretboard ext with some heat, then heated that sliding dovetail while repeatedly applying pressure in different ways, since I didn't know anything about the joint, until things started to loosen up and I could what I had. I used a clothes iron over the joint for the heat.
Neck came off nicely with no damage (pull UP, straight off the body), I adjusted the angle, repaired some minor wood removal, then simply slid the dovetail back together after installing another interior bolt/receiver to hold the neck in place. I left the fretboard unglued, but no buzz means it's now it's a bolt-on dovetail with intact full scale that I can pull apart for adjustment in 10 minutes.
Great guitar that sounds great, too.