Cloth Seal, Stuart Arms, Alnage

Cloth Seal, Stuart Arms, Alnage, Image & Found by Neil Pitcher.
Found on the Thames foreshore, 18mm.

Missing // Stuart arms of Britain, (C?) R to sides, 16(4)8 above (4 retrograde?)

An inner disc from a four-disc alnage seal from the reign of Charles I if the unclear numeral is a retrograde 4.