After scouring Ebay for a couple weeks, I eventually found a Rolleiflex  Automat MX-EVS with a Carl Zeiss Tessar 75mm f/3.5 lens.  It was in pretty amazing condition.  This particular model was made between 1952 and 1956, and was the first model to couple the shutter speed and aperture dial according to Exposure Value (hence EVS). Rolleiflex's in particular are built like tanks, and are a thing of mechanical beauty.  The way everything perfectly fits together and the smooth, solid movements of the knobs and switches are just spectacular.