I know quite a few people who are into decluttering these days, and one of them was throwing out some 35mm equipment but didn't attach a name to them. So I asked about the lenses and he sent me these.
42mm thread mount, 135mm, 35mm, a 2x teleconverter and a selenium light meter, all with the "Prinz" name which was a brand used by Dixons back in the day (which suggests the camera may have been a rebadged Zenit E and I definitely don't need one of them).
As you can see in the second image, the lenses aren't auto, they have kind of a preselector mechanism. Set the top ring to the aperture you want, set the front ring to the aperture you want, turn the inner ring anti-clockwise to open up the diaphgram, then turn it clockwise to stop down to the preset aperture. I have never heard of that before!
Have a couple of cameras with 42mm thread, but very few lenses, so I shall give these a try some time soon!