For sale is a very interesting and very early Japanese-made guitar.
 
Branded 'BM' for Barnes & Mullins, I highly suspect these were built by the same people that created the Japanese 'Zen On' equivalents for the American market.
 
These were very early Japanese-made models and feature a fair few quirks. To my eye, the are highly modelled after Harmony/Kay models of the same period and resemble them uncannily in body shape.
 
It is technically 'working', though owing to how they were built does require some work.
 
The pickups are incredibly low output - I had a similar 'Zen-On' with very similar pickups that had the same issue.
 
For some reason, they lacquered over the the (open) rosewood fingerboard at the factory. There was flaking lacquer over the frets themselves (I can only wonder as to why they did this). The electronics will likely need attending to and the tuners are very stiff.
 
Interestingly the truss rod cover... covers nothing. This was a purely cosmetic appointment, again I feel in the vain of emulating a Harmony or similar - without building it in the same way.
 
The action is somewhat playable, but the board fishtails somewhat dramatically from fret 12 - onward.
 
Near all parts however appear to be original, save for the odd screw / fixture. There is a previous repair to the f hole area as pictured, owing to the very thin tops they used.
 
So while it technically plays somewhat, the abovementioned issues will need to be attended to. The guitar has potential and I think it's quite a handsome design, but needs work to be made into a properly playable guitar. I believe it shares a lot of parts with other Japanese-built guitars of the same period, so may be of some utility to someone in that regard.