I've just accidentally stumbled across a reference to the Roman Worthgate (Canterbury) in a totally unrelated letter. This letter is dated 13th June 1951, from the Chapter Library, Canterbury Cathedral, and addressed to the Ministry of Works. The topic, as I say, is unrelated - all about
St.Margaret's Church - but at the very end of the typed document is this handwritten note and sketch which I've attached as an image. It reads:
"P.S. The Roman Worthgate of Canterbury has come to light at the back of a country house at Littlebourne near here - removed C. 1800."