A. Schacht Ulm R. Travenar 1:3.5/135mm

This lens came with a Praktiflex FX that I purchased (pictured below).  It appears to be from roughly the same period, and has seen a fair amount of handling.  It is an early pre-set design that has an interesting twist - the preset mechanism is spring loaded and "automatically" sets the lens at the proper aperture when released.