BSG.CS.01562 — Cloth Seal, Crowned Monagram?

Found on the Thames Foreshore, 37mm.

Undeciphered design // possible secondary stamp of crowned monogram G or C over YM ligate ?

Unusual shape and marked cloth seal.

From the finder, "I seem to see a crown above interlinked letters or a motif on the left side. With a C or G above interlinked Y W or V. Part of a building on the right hand side?"