Paul, I dunno about it being factory left-handed, I can't buy into that just yet....but I see where you're coming from.
These guitars would have had to be purpose-built instruments from a construction standpoint no matter what direction they pointed, issues like the shape of the neck where it attatches to the body and the body itself in relation to the cutaways. A Mirror-image headstock by itself doesn't make much sense to me for it is only for aesthetic purposes only and wouldn't affect the guitar's playability either right or left handed.
As I said earlier Fender was the only one doing a mirror-image lefty in the 50s, Gibson simply flipped their neck due to it's asymmetrical design. Rickenbacker's lefty necks were right-handed and flipped on the hollow-body and neck-thru models until the late 80's....
Anything is possible, but what we see on this guitar goes against the grain of what they did with everything else. While maybe not lengthened or shortened, to my eye it does look narrower and the tuners seem to be spaced differently then most of these Combos that we see. Who knows..
Oh yeah, the wear on the body plate and the nut (to me) looks like it was from a right-handed player.....