I discovered a nice, lengthy biography of Pete Wendling, the QRS
piano roll artist, at the web site of "Perfessor" Bill Edwards.
The compiler is Edwards himself, as he is both a fine ragtime piano
performer and a good historian.  He thanks MMDers Robert Perry and
Andrew Barrett for recent additional information about Wendling.

"Perfessor" Bill tells how Wendling was hired around 1912 by the
Frederick A. Mills music publishing firm as a "song plugger" to
demonstrate their new songs for customers: "His reading skills were
sufficient for learning pieces, but his playing was well beyond that
of the average plugger, giving him an edge."

In describing Wendling's QRS piano rolls, Edwards says --

  "Pete was the first to admit that he was only a performer for QRS,
  not a music or roll editor by any stretch. His input consisted of
  doing one or more takes on a markup piano, which simply put pencil
  marks on a roll as he played. The editing was then undertaken by QRS
  experts, including Kortlander and the legendary J. Lawrence Cook."

Much about Pete Wendling, his life and his compositions, is
presented in the composers section of "Perfessor" Bill's web site, at
http://ragpiano.com/ and  http://ragpiano.com/comps/wendling.shtml 

Robbie Rhodes - Mechanical Music Digest