Post Office GPO Round, Eagle & Dolphin Seal, 1691-1708

Post Office GPO Round, Eagle Displayed & Dolphin Embowed Seal, Image & Found by Ash.
Found in North Yorkshire.

Seal with so far unidentified coat of arms on consisting of a two ringed border (one raised continuous line circle with a circle of pellets outside that) inside the rings is a design of two ovals with decoration above that looks to be two dolphins with their tails entwined. One containing XX in a top section above a dolphin embowed and the other containing an eagle displayed with no top segment. There is a five petalled flower between the lower edges of the ovals that terminate ornately. The other side has the standard GPO Crown over POST.

Updated discription after seeing PAS record WILT-AFD0C4 identified by Mr David Algar:-
"A Post-Medieval Post Office lead bag seal from the reign of William III (1689-1702) and Anne (1702-14) of the House of Stuart. It measures c.20mm in diameter and c.4mm in thickness, weighing 10.85g. It has slight wear and a perforation from one edge to the other where it has been cramped onto a cord.
Obverse: Crown above G·POS[T] (General Post) Reverse: Two oval shields, on the left, an eagle displayed, head left and on the right, a dolphin embowed left with two saltires in chief. This seal would have been used to secure the contents of mail bags or sacks. Date: 1690-1708 The seal bears in the oval shields the crest or arms of the senior and junior Postmaster General who held office from 1690-1708: Sir Robert Cotton [The Royal Mail Archive gives his date as Postmaster General as 1691-1708], an eagle displayed, and his deputy Thomas Frankland, a dolphin embowed below two saltires in chief."