Antique MINTONS Vanity Tray All Hand Painted Pink Roses Blue Forget Me Nots 1861

ANTIQUE MINTONS VANITY TRAY

Entirely hand painted with pink roses and blue forget me nots with gilded edge

12 x 9"

Here's the conundrum:

Underglaze impressed date marks for February 1861
Additional underglaze impressed shield form mark
OVERGLAZE green Mintons mark dating 1873 onwards.

I am betting this was an earlier blank (from 1861) that was pulled out later and decorated and stamped to be sold

Draw your own conclusions from the above information