20 Pounds

Guernsey's higher-denomination issues from this period are often overlooked in favour of the Channel Islands' earlier chartered bank material, but the Brown/Trestain signature combination is the less common of the two pairings found on P#55 — Trestain replaced an earlier treasurer mid-series, making mixed-signature sets a minor collecting target.

De La Rue's security thread specification on this series predates the windowed thread technology the firm introduced commercially later in the decade.