Cross Penny Post: Boxed "No.4" in c.1838

The Receiving House at Cheddar used the boxed "No.4" handstamp firstly in the Wells Penny Post from 1816 and then in the Cross Penny Post after it was established in 1827.  The undated item below went in the Cross Penny Post from Cheddar ("No.4") to Banwell (which had the boxed "No.3" handstamp).

Because the "Cross / Penny Post" is in blue/green, the piece must date from 1837-1839.