I second John Klungle's statement about what pianos Grinnell
marketed.  Although they did manufacture some of their own pianos
(they had a factory in Holly, Michigan, near me), other brands received
their name.  I recently restored a 1915 Grinnell "Playtona" 88-note
(foot-pumped _and_ motorized, all original), and the only thing
Grinnell about it was the name on the fallboard.  The name on the
plate, and everything inside, was Aeolian.

Dan Harrett