I have sought advice and it appears that this might be a rogue, lost and lonely caper, that may well be the last survivor of its species in our area as the decline in the species has been massive in recent years. These lost capers have been known to venture close to humans and appear fairly tame, but remember it is a wild bird and should not be approached.
It is at risk to the dangers of living so close to town and probably will not survive. I am seeking further advice about the best way to 'help'. I'll keep you updated.
By the way - on my way home in the increasing gloomy light, I spotted these on a Long-Tailed Tits on a feeder - lovely!