Five Golden Hours (1961)

A petty crook is doing all right in his chosen profession of gallantly consoling wealthy widows--until he meets and falls in love with a lovely baroness who knows all about get-rich-quick schemes. The crook evolves an ingenious swindle geared to the time differential between New York and Rome and works it on his string of widows, but the baroness takes off with the dough. The crook flees to a mental home to escape the wrath of his victims.