I have a 1918 QRS Player Roll Catalog.  The first page shows the
meaning of QRS which reads

      "QUALITY REAL SERVICE"
  Player Rolls For all Player Pianos
  Manufactured by: The Q.R.S. Co.
  412 Fine Arts Building Chicago, USA.

This catalog measures 5-1/2" x 8-1/4" and 3/8" thick, with full
page photos of all artists.  Prices ranged from $.45 to $1.00.
I was surprised that QRS did not know the meaning.

Gary Heckman