The Kingston Trio, Limeliters, and the Brothers Four are now doing a concert tour together. see here: https://www.mayoarts.org/shows/the-kingston-trio
An acquaintance of mine, Daniel Boling, was recently selected to be a member of The Limeliters, and he has been enjoying the experience. Daniel is a good songwriter in his own right, and built his reputation singing his own songs. No, he's not traditional, but he does good stuff. He's a former park ranger with an interest in history and ecology. He'll do fine.
No doubt, Rick Fielding would have done well as a member of any of these acts.-Joe-