It is a simple camera to work out, the simple manual will tell you everything you need, If you have changeable lenses then yoy can't have the Werra Mat as the matis a fixed lens model, maybe you have the Werra Matic? that is the nearest in name that has the interchangeable lens feature, I have 4 Werra's, the Mat, 2 matic's and a werra 3, which is an early model with the interchansable lenses and they are fine lenses and cameras, they were ahead of their time, but there were changes in the models as they were improved over the years, they have a breech lock lens mount,there is a milled ring to release the lens, and after a lens change you must turn the aperture ring both ways to connect it to the lens aperture,and the rangefinder spot is one of the easiest to use, with a split image similer to an SLR split image, and works well, the meter is used via the viewfinder in all but one of the earliest models (The 3 ) and again I have found them very reliable, just set the shutter speed and adjust the aperture untill the needle is centered in the viewfinder, the exposure counter is underneath and is hard to use, but can be used, just turn the black knurled ring in the center to the first exposure after firing off 2 blank frames, apart from the above their is very little to learn and the small manual will tell you all you need to know, but be careful as the manual covers all models, not just the one you have,so have fun with it. Shame you live an ocean or more away, on the other side of the world to me as I have both manuals that came with the cameras I bought, if you want to know anything else let me know and I will help if I can
Richard