Pretty much spot on, Andy. :)
I think they were introduced in 1980 and only lasted a couple of years. Note the odd position of the selector switch, similar to SGs from the same period!
It was right about the time I started reading equipment reviews in the back of Sounds and occasional copies of International Musician and Recording World, which is why I remember them quite well. There was a bloke called Gary Cooper (not the star of High Noon, presumably) who reviewed the 335-S and actually bought one.