I have owned several Japanese guitars, acoustic and electric, made in the '60's. Each of them was a perfectly useful guitar after lengthy setup, except for one acoustic, which, after extensive rebuilding, is now my main acoustic ax (details below).
The early '60's Japanese guitars, as someone already noted, were roughly the equivalent of current Chinese, but without the CDC machines. As the decade progressed they got better and better. There's a reason you see them for sale "cheap."
All of the electrics were useable, even though a couple were pretty ugly. One came with an amplifier I paid $40 for. The necks were OK, the sound not much, but intonation was good and they responded to setup.
Two of the electrics were solid, two more were thin archtops. I still have one, a Ventura Chet Atkins "copy" w bolt-on neck and single coils. Both had cheapo Bigsby knockoffs, with pitiful bridges. Both bridges were replaced with tunamatics, and the Chet Atkins eventually got Gotohs. Again, the necks worked fine with a little setup, and the sound was much better than the solid bodies (maybe they were later).
Two acoustics: a 6 and a 12. The 12 was a copy of a D-28-12, and decent, but with a thin neck. The 6 had a horrible plywood top: nice close grain spruce on the outside, Phillipine packing-crate mahogany on the inside, with braces laid out like floor joists. It too had a thin neck, and is still in my collection, with the substitution, by a local luthier, of the plywood with bear-claw spruce, a Guild-style bridge, and a neck reset; it also has Gotoh tuners now. I had the luthier leave the Japanese label inside.
The prices were reasonable: solid bodies: one for free with an amp (an excellent 1963 Sears Silvertone Twin Twelve, which I still have -- best $40 I ever spent), the next one $7 at a garage sale, $20 for one archtop ditto, $75 for the "Chet Atkins", $35 for the 6-string acoustic and $45 for the 12.
They are great to learn to tinker on, and you can usually get the action pretty good, and if you don't -- you can sell it to the next guy on eBay.
