Photo 1 shows a cold shoe, where you would normally mount a viewfinder--either a zoom finder or a wire-frame finder usually, the latter with a sight in the shoe and the wire frame on the front standard. The rangefinder is the thing with an eyepiece on the back and two holes on the front on the right side of the camera. To work, you need a cam in the camera specific to the lens and the camera body (serial number matched to both), and the rangefinder needs to be in good calibration. The viewfinder and the rangefinder operate independently from each other, so you need to set the subject distance and focal length on the viewfinder to frame after focusing with the rangefinder.
Is there a level in photo 2? If there is, it's for leveling the base of the camera. There is also usually a bullseye level on top of a Tech III. Some Technikas have a block for mounting a cable release in the spot you've circled in photo 2, but cable releases that fit there are no longer made and are hard to find.