I believe this lantern to be an BTH Rural Open. The canopy and the refractor assembly clearly matches BTH lanterns.

It is missing its refractor and refractor hooks, but the rest of the lantern appears complete. It doesn't have the BTH logo on the canopy either, suggesting AEI provenance, but I don't have any evidence that AEI made this lantern.

It's fitted with a 2-pin porcelean lampholder so would've originally taken a tungsten bulb.

It originally stood in Braintree, Essex, where the lighting engineer rescued it from the skip - good man! As a sawn-off finial was included, it was probably removed when the street light was converted to side-entry sodium.