There are portraits of Dr John Murray and his wife Mary Boyles at the Norolk & Norwich Hospital in Norwich, England.They bear the following inscriptions:
John Murray MD 1721-1792 of Norwich England
This copy was made in 1899 by Margaret Lesley Bush-Brown great grand niece of John Murray from an original owned by his descendants Edward and John M Guion, Seneca Falls, New York.
Certified Bronson Murray New York 1899
That is on the back of the portrait, and on the front:
John Murray MD 1721-1792
Founder of the Scots Society in Norwich 1775 presented to the Scots Society of St Andrew, Norwich by Bronson Muray Esq New York
April 1899
Mary (Boyles) Murray's (1730-1819) portrait has similar inscriptions.