Ah, interesting and unusual - even in the day I don't recall seeing many of these.
I've owned an MBK 'Trainer' since 1992: I'd be reasonably confident that it's the same frameset, but the 'Trainer' was originally fitted with a pretty much bottom end Shimano groupset. Mine's been upgraded to a mix of 105/600/Dura-Ace as things have worn out, and it's been ridden for years as a day-ride bike.
I've not long got a Condor Fratello for that job, so the MBK has been converted to a SS and now gets used to whip about town on.
Terrible picture tho' I grant you ...
I've also seen this frame design in a step-through 'ladies' frame shape too, which actually made for quite a pretty looking bicycle (of it's type).