Unidentified Stamp

Unidentified Stamp
Dimensions (height x width): 29mm x 26mm
Monogram: P A M C
Initial: P A M C
Coronet: Marquess
Notes:
The monogram appears to be a combination of the letters P M A C surmounted by a marquess’s coronet. The publication dates of the books cited coincide with the dates of Harry Powlett [Paulet], 4th Duke of Bolton (1691-1759), known as the 9th Marquess of Winchester until his elevation to the dukedom in 1754. However, the initials do not match.