This company produce postcards of schools and other institutions, to be sold by the institution. Older cards were published from Tower House, Trinity Square, London, E.C. while later ones were published from Hampton, Middx. On google I found the statement "Before the war printing was carried out by Trenkler of Leipzig [the distinctive printer’s numbers being the give-away]; after the outbreak of war they were printed at their own ‘works’ at Hampton Hill."

The cards of Lockers Park were probably taken in the 1930s.