Portland Match Company
The picture on the Portland Match Company stamp is that of Willard T. Brown, the owner. His business ran from 1865 until he sold it to Byam & Carleton in 1867. The stamp were issued from May of 1865 until December, 1867. 5,867,000 were issued on old paper.
The Portland Match Company wrappers were issued from October of 1866 until December, 1867. 3,575,000 were issued. Most of the existing copies do not appear to have been used, and are dated December, 1866.