There are two things I would like to add to the discussion, First 78s were out of favor in the U.S. by 1957 and production by around '58. The 45 was king from '56 on. Also, in the last years of the 78 most were made of an unbreakable plastic and improved fidelity but the heavy-handed (or should I say heavy- armed) players were no match for the new high fidelity players.
"Does Your Chewing Gum Lose Its Flavour . . . " was recorded as such because at the time, "Spearmint" - as was incorporated in its original title (written in the 1920's by Billy Rose, Marty Bloom and Ernest Breuer), "Does The Spearmint Lose Its Flavor . . . " - was a trademarked name, and thus would have run it afoul of the BBC's ban on advertising in popular records. And back in 1958-59, the BBC was the only game in town on the radio - and Donegan evidently and obviously was aware of this.
There was no corresponding 78 RPM issue of the U.S. Dot release #15911, as the industry there had largely abandoned this veritable but brittle (literally, given how shellac records tended to crack easily) format over the prior year.