Green’s Dictionary of Slang

(UK Und.) a confidence trickster, well-dressed and well-spoken, and without any visible weapon, who poses as a gentleman down on his luck and tells his ‘tale’ to the passing victim whom he picks up in the street. They also stay in hostels from which they leave early, paying no bill but taking the bedlinen with them.

c.1561		Awdeley Fraternitye of Vacabondes in Viles & Furnivall (1907) 6: A Curtesy man is one that walketh about the back lanes in London in the day time, and sometime in the broade streetes in the night season, and when he meeteth some handsome yong man clenly apareled, or some other honest Citizen, he maketh humble salutations and low curtesy, and sheweth him that he hath a worde or two to speake with his mastership [...].
1925		E. Jervis 25 Years in Six Prisons 130: He was the collector for an insurance company whose premiums are collected weekly. Sometimes these men are called ‘body-snatchers.’ The woman was his courtesy-wife. She went to the registrar of deaths at Fulham and handed him a medical certificate which pretended to certify that her husband was dead [...] Armed with that certificate, she went boldly to the office of the assurance company and obtained £12 16s. on a fully paid-up policy on the life of the ‘deceased’ husband.