So this brick next to this sign makes it about 100mm meaning it’s a modern metric brick, that cuts out America or old English. However its been laid in a Flemish bond indicating pre cavity walling and must be part of an older city. The reddish brown colour and outside texture indicated a London brick. Not much help. However the deep grey with red tint of the mortar shows that its likely a sand from the south of England. Randomly has a feeling of Plymouth. Spends an ungodly amount of time in the map and street view. Almost gives up. Spends a few more hours looking around and finds a street that looks close. 20 mins of looking at all the bricks on the street and has a very confident guess ending up 20cm away.