Cloth Seal, Unknown, Continental, Rose, Two Shields

Cloth Seal, Continental, Rose, Two Shields, Image by Derfel, Found by Peter Olivant.
Found on the Thames foreshore, 22 mm.

Rose // two shields each with two tinctures indicated per bend, privy mark? between, crowned double headed eagle above.

The rose suggests English but the double-headed eagle suggests Continental.

From Mark Jennings, "it could be Holy Roman empire their symbol was a crowned double headed eagle, I found two towns with a rose as a symbol Rosheim and Haguenau, I could not find anything on Rosheim, but with Haguenau you have a seal BSG.CS.01346 they also grew hops, could it be a Hop seal? Borough market on the south bank of the thames had a large Hop exchange and imported hops from abroad."