I picked these up yesterday as they were only down the road. Paid too much as it turns out (see below) but interesting anyway:
The model is MA 20, dating (according to marking on the bass driver) from around 1980. I've never heard of them. The internet has never heard of them. The people who remain at Monitor Audio have never heard of them. Their best suggestion was that they were likely some low volume series that Mo Iqbal created (something that apparently he made a habit of).
I could see from the photos that the mid ranges (Audax units) need re-foaming which isn't a problem but the first one I removed and tested is open circuit. Add to that, one of the bass driver voice coils is rubbing (I gave them a prod on collection but it would seem unfortunately prodded the side of the cone that pushes it clear!) and it's already looking like an non-economic repair.
Never mind.
Should be some pictures - can't get ImgBB to play at the moment...