Beardedbruce - thank you very much for the results of your research!
I suppose that this very talented artist wasn't really recognized by a record company in those days apart from these 2 tracks. And even these recordings seem to be coincidence more or less because these tracks were made on one of "the annual provincial tours undertaken by the major companies from 1924 onwards in quest of untapped talent." In this case, an unknown talent scout of RCA has to be praised to select Sugar for recording 2 very different tracks. Thanks to him! And shame on RCA that they did not produce any follow-ups with Sugar Underwood. I can't believe, that these 2 tracks didn't sell. But-naturally-I don't know.