Cloth Seal, Cloth Worker's Personal Seal, Initialled, E
Cloth Seal, Cloth Worker's Personal Seal, Initialled, E, Image & Found by Rosie Thomson.
Found on Thames foreshore, ?mm.
47 1/2 / E
The scratched number is almost certainly the length of the cloth in yards.
The E could be the owner, manufacturer, supplier, the official who measured or approved the cloth, or even a quality mark.
From Egan, Lead Cloth Seals and Related Items in the British Museum, "incuse numbers are generally found on two disc seals of eighteenth-/nineteenth-century date - i.e. post-alnage."