http://www.ebay.com/itm/Porcelain-Lincol...=item415e839534the shelving appears not to be high enough (the original 1916 Lincoln signs of that style had extremely high shelving that would be clearly obvious when a light is reflected point-blank off of it as in that first photo)
the back is far too uniform gray, as opposed to having the rack marks which are common to genuine porcelain signs of this era.
http://shields.aaroads.com/img/CA/CA19280992i2.jpgthe grommet is a style that wasn't around in the 1910s - a genuine grommet would have a "petaled" back as they were made with the petals unfolded, and installation of the grommet meant folding the petals down to wrap around the sign. the "rivet style" grommets which were deformed into place were invented later: 1930s or so.