This Demorest sewing machine is the The Lycoming Museum. Lycoming is the current name of the company that used to manufacture Demorest sewing machines. They now manufacture aircraft engines. They have a company museum that is open to the public.
This machine is circa mid to late 1890s. It has the later style rectangular bed machine but it still has the coffin top and "Demorest" cast into the irons. The center cabinet drawer is split and swings out in opposite directions. This is a later style cabinet than the ones shown in an 1892 ad, and is shown in later ads which also feature drop down cabinets.