This is not much use to you Neil but I used to have one.  It was definitely bought from a catalogue, probably Kays and it looked just like a crosser with mud guards and dampers.  It had 'suspension' front and rear and was super HEAVY!!!  My mate fell off the bloody thing doing a jump and damaged his neck really bad - he still can't straighten it properly to this day.  I owned it in '81 I reckon but this is all I can give you.  I'll have a look for a pic later.