Cloth Seal, County Alnage, Image & Found by Ange.
Found in Lincolnshire, 20mm.
A two disc seal showing a crowned portcullis with the letter R to the top right and a Roman lettered inscription around of which only (O?).M remains. On the other side are Roman numerals, X.L.III with possibly another I at the end.
See:- PROVENANCED LEADEN CLOTH SEALS by GEOFFREY EGAN, Sub-Department of Medieval Archaelogy, University College, University of London. submitted for the degree of Doctor of Philosophy, 1987, "The most common later 16th-century county stamps have a crown over a portcullis, with Lombardic- or Roman-letter legends (fig. 13A & B). The other side sometimes has Roman numerals for the weight in pounds of the cloth, or an alnage-officer's privy mark. The portcullis stamp often appears alone. This series may well have originated in the early 16th century, ... Counties represented by seals with Roman-letter legends are Somerset and Worcestershire ... Further examples have Roman numerals apparently from VII to XLIII, probably for the cloths' weights in pounds (cf. 1566 legislation) on the other side from the stamps with the portcullis."
So probably a late sixteenth century county alnage seal from Somerset or Worcestershire attached to a length of cloth whose weight was 43lbs.