The mug was made by Dithridge as their Pinafore (OMN) mug at their Ft. Pitt Works c1880. A trade quote mentions the moulds being made for this mug and the related Bo-Peep mug in October 1879. (Sid Lethbridge, 2018) This cup is done using crystallography and has HMS Pinafore and Buttercup pressed on along the base.