E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A man who steals the lead off of a house or church. Bluey is slang for lead, so called from its colour. To pigeon is to gull, cheat, or fub. Hence, blue-pigeon, one who cheats another of his lead, or fubs his lead. Flyer, of course, is one who flies off with the stolen lead.