I've never heard of a Sachs 134 before, so this is good info. I do remember having two Dolmar 9000s though when I worked for the Forest Service, and one had the clamping knob in the center of the filter cover like this model does.
Jacob J was the first to figure it out. There are probably only 3 arboristsite members that would of known the model number. Dolmar_Tech_Mgr, Cuttinscott, and myself!