This is a great doubleneck, as the body is pretty well standard size. I have modified this with separate outputs for each neck (there’s also a shared output).
Brass nut, the tone on this is superb. Not a common guitar, this has a very low serial number, and I have seen later ones with a scratchplate added.
There are a couple of active FaceBook pages for Daion enthusiasts, with a wealth of information about the brand.