The Western Pianoforte Manufactory was a small, short-lived company which was established in 1856 by Charles L. Thomas in Hamilton, Ontario. In 1858, Theodore Heintzman closed his firm in Buffalo and moved to Hamilton to become a partner in The Western Pianoforte Manufactory. Heintzman gradually took control of the firm, and in 1860 he moved to Toronto to establish the now famous Heintzman Piano Company, one of Canada's largest and most successful piano manufactures.
We have only known of a couple pianos under the "Western Pianoforte Manufactory" brand name to exist. Since Thomas and Heintzman built instruments under this name only from 1856 - 1860, they were built in small numbers. They are exceedingly rare and of museum caliber today.