Cloth Seal, Norwich Seal, Image & Found by Jason Sandy.
Found on Thames foreshore near Swan Lane between London Bridge and Cannon Street Bridge, 19 x 15mm.
Stylised rose (I?) (F or P) above, annulet above that, (T?) (B or P) below // castle lion below
Lion (passant, gardant) in front of the castle shows it to be a City of Norwich seal rather than a Norfolk County seal. A similar seal suggests the letter to the lower right is a B.
No mention of this stylised rose has been found but this is the second such seal discovered on the Thames foreshore.