The Sons of the Pioneers last two original members retired in 1949 yet their best known record came out in 1959, a stereo LP on RCA called "Cool Water". I prefer most of the versions of their classic songs from that album. Their "classic lineup" was great, especially Bob Nolan's singing and Karl Farr's wonderful guitar work, but both lineups "authentic" in their own way.

It does not necessarily follow that the current Kingston Trio is a worthy replacement for the original, but it is "the only game in town".