This just in from Jim Korkis:

[Even on the internet, a researcher can sometimes stumble across the most obscure Disney historical information in the oddest of locations. One of my favorite Disney animated features is "Lady and the Tramp" and unlike today when celebrities are cast in the vocal roles, in those days finding just the "right" voice to capture the character was very much important whether the performer was well known or not. In the film, Barbara Luddy provides the voice for Lady and she continued to supply memorable voices for other Disney animated characters as well. However, the voice of Tramp was done by actor Larry Roberts who despite some success on stage and in early television is largely forgotten today. However, here is some information about the actor (including a photo) that may be of interest to fans of the film like myself.]