On the 1921 census John and Grace Davidson in Ogbourne St Andrew (no precise address) have a visitor. He is Edward Alexander Dell Davidson, John's brother who lives in South Africa.
Passenger lists show Edward arrived in the UK on 11 June 1921 and returned to South Africa in August 1921. On his return journey his last address in the UK is recorded as The Box, Ogbourne St Andrew. I can see a Box Drive (off Rockley Road) in Ogbourne St Andrew but Street View won't let me go up there.
I'll have another look later.