I just had a Rawson aperture sight installed on my N°1MkIII SMLE. The piece is complete with all screws, plates etc and fits perfectly on my rifle.
Nice sight. When I had my old Ishy .308, I scoured Flea-bay and gunbroker looking for a reasonably priced Rawson, Parker Hale 5a or Central. I kept getting outbid because I couldn't justify spending more on the sight than I did on the rifle!