Cloth Seal, Norfolk / Norwich, Lombardic N, Image & Found by Darren White.
Found in north east Leicestershire, 18mm, 5.97g.
Three turreted castle // 3 pellets above Lombardic N with rectangular design at its centre
Possible lion passant below Norwich castle would indicate the seal is specifically from Norwich rather than Norfolk in general.
The Lombardic N appears to have three pellets rather than a crown above it and a window-like design at its centre.
A seal with a very similar N but crowned and with three pellets to the left is shown in Egan, Geoff, Cloth Seals, p.43-86 in Salisbury & South Wiltshire Museum Medieval Catalogue, Part 3, ed. Peter Saunders, 2001, no.21, Fig.20. It is identified, along with no.22 (probable large Lombardic N and Norwich castle on the other disc) as being a Norfolk / Norwich seal.
The Lombardic N on these seal can, in isolation, be confused with the seals of Naarden.