U+2122 character ™. But the design stuck, and even after death, they are still known incorrectly by those names.
From 1925-1934, the Smith Brothers company decided to exploit those branded and bearded faces and sponsor a radio program on WEAF-AM. Harold "Scrappy"
Lambert and Billy Hillpot played the parts of Trade and Mark Smith, the fictional personas of the real Smith brothers. The book Sold On Radio by Jim Cox list Smith Bros under it's advertiser index selling their cough drops on the radio with just the one program. Radio was new to Smith Bros, but it was just as new to Scrappy and Billy.
Lambert and Billy Hillpot actually met in college at cheerleaders at Rutgers University in New Brunswick, NJ. Scrappy was born in 1901, and while Hillpot's date of birth is unknown, he graduated in 1926 so he might have been just a tad younger than Scrappy. Regardless they were both in their early 20s at best and by all reports it was a gig they got right out of college.
Jack Pettis. More here.
In 1943, MCA offered Lambert an office job managing various artists and productions for radio. The year before, Hillpot left the NBC Artists Bureau. Shortly thereafter he got an even bigger job as a 'radio executive' for OCIAA (formerly OCCCRBAR) but aka (The Office of the Co-ordinator of Inter-American Affairs.) It was a WWII propaganda department. Both had gotten out of singing by the late 1930s. Lambert stayed at MCA until 1948 when he went solo as a talent. True to the spooks he worked with, Billy Hillpot more-or-less vanishes at OCCIA. An August 1942 issue of Broadcasting names him as Director of their New York Office. The group was renamed (OIAA) the Office of Inter-American Affairs (OIAA) in 1945... but Hillpot has already vanished.