Dr. Fasser's collection came with a twine-bound set of 8 slides marked "Rheims", a common alternate spelling of Reims. But given what's on the slides, he couldn't have made them all himself - so we must examine the evidence to try to suss out whether Fasser ever did photograph Reims.
One of the items in Andrew O. Fasser's collection of stereo slides is a box, which originally held Verascope Richard 6x13 diapositives, simply marked "Belgium". Inside are 16 slides of Great War devastation; the best 8 are examined.