The flint cottages where the platoon march after rescuing Pike from the bog have been known as Percy Street in the series. However, at one point a sign bearing the real road name (Nether Row) is clearly visible in the background in a shot where we see the platoon march past the Verger and the ARP Warden.
The episode is set in 1940. However, one of the groups in the parade is the "ATC" or "Air Training Corps", a cadet organisation linked to the RAF. However, this wasn't formed until 1941. In 1940 the air cadets were still known as the "Air Defence Cadet Corps", part of the "Air League". And, indeed, in the parade the cadets are wearing Air Defence Cadet Corps uniforms, which are based on WW1 Royal Flying Corps uniforms.
When chasing the ram, Pike says it reminds him of Gary Cooper in The Last of the Mohicans. Randolph Scott starred in that film, not Gary Cooper.