I'm a bit late adding to this post but....
It is definitely a 1980's VOX White Shadow. Not sure if the 5th string was added later as I haven't seen a 5er.
I used to have one,
I lent it out about 9 years ago, then he lent it to someone else and it hasn't been seen since.
If anyone sees one, it's fretless, black with orange trim. It too has a fitted case with a gold fleece lining, please let me know as I would love to find it and possible get it back (though I know there isn't much chance).
Thanks