The first item of interest is the note scribbled on the envelope - Retina 2S Oct 67, which refers to the Kodak Retina 2S camera, a model made in Germany between 1966 and 1969. Presumably, this is the camera used to take this reel of film.
A picture is available on Flickr.
The folder contained 11 pictures. The set includes what appears to be a duplicate of the photo showing the Corgi by the stone-engraved motto, but which may be two photos taken in quick succession without any apparent movement.
Some obvious clues from the photos, they own a Corgi called Peggy, and they live in a bungalow. Judging by the chimneys, the bungalows I would date around the 1950s and 1960s. Nearby is Priory Park, and possibly within the park or in the surrounding area, is an area called Churchill Gardens?
Their bungalow is called Cherwell, which indicates it is not near Cherwell.
While researching Priory Parks, associated with Churchill Gardens, I stumbled upon Southend-on-Sea, which has two parks located next to each other.