Sorry but this is probably a couple of years late

but, I bought one in Feb 1981 and I’ve not found another guitar that I’d want to replace it with.

The only information other than the original instruction leaflet that came with it that I can find is at http://www.vintageguitars.org.uk/sonex.php

Mine came with a hard flight case that even now maintains that distinct new aroma it had when I bought it. I’ve only ever seen three, two in separate music shops in Dundee, Scotland in 1981, one of which is now mine. and more recently a couple of years ago in Sound Control also in Dundee, they had one that they were using it in a sound booth to demonstrate amps, effects units etc. I’ll never sell mine its just irreplaceable