It does have coating at all surfaces. Single-coated Tessar lenses are supposed to be contrasty. There are only three optical groups there (!)
Something must be wrong with your lens or camera. For example, a plethora of tiny micro-scratches at the front surface can wipe off contrast. Same with haze.
Or perhaps you are not covering the lens against flare / peripheral light sources.
I may have misled you - they are not hazy. The lens isn't defective - there is some contrast, just a good bit lower than I prefer (you and I probably have different tolerances). It is the same as some of the other cameras I have from that era, such as my Super Ikonta. I have run many rolls through them, so it is not a matter of technique. The front and back elements are glossy, so it is not from micro scratches. I just do not prefer the softer contrast of these lenses. They perform fine, just not as well as my Mamiya Six or Autocord, or more modern lenses.
I like the camera. I am not coming down on it. I just like it better with a filter.