O. P. Co. porcelain signals
   The Ohio Porcelain Company, located in East Liverpool, Ohio,  began manufacturing in 1897 and would become property of G.P. Co. sometime between 1911 & 1913.
Reported styles: U-274

Reported colors: brown, white
This very scarce U-274 is embossed on upper side of wire groove ridge "O.P. CO". Owned by Jim Colburn.