Clifford Glenn and his father, Leonard Glenn, actually made many if not most of the instruments that were sold by Frank Proffitt, Sr.in the early 1960's. Frank Proffitt, Sr. was too busy playing folk festivals, building a new home financed in part with money obtained from the rights to "Tom Dooley", and working his small farm. I corresponded regularly with Frank Proffitt, Jr. prior to his untimely death in August of 2005. I even ordered a banjo from Frank Proffitt, Jr., but the banjo was actually built by Clifford Glenn of Sugar Grove, North Carolina. Clifford Glenn stopped taking new orders about two years ago, because he was 2 to 3 years behind in filling his orders. I just recently received a mountain dulcimer ordered from him in 2002. His instruments are well-worth the long wait, but I fear he is no longer making the instruments.
As others have mentioned, Keith Young makes one of these mountain-style fretless banjos. Keith has a website where you can look them over. Another excellent source based on the Stanley Hicks design is John Huron who bases his models after the Stanley Hicks pattern. His models can be found online as well. Search online for "Noteworthy Instruments". By the way, Frank Proffitt, Sr. was married to Bessie Mae Hicks, a cousin of Stanley Hicks. Bessie Hicks was the daughter of Nathan Hicks, who made the banjo played by Frank Warner. Stanley Hicks was the son of Roby Monroe Hicks, Nathan Hicks's paternal uncle. If memory serves me correctly, the Keith Young banjos run about $400-$450 and John Huron's banjos are about $350-$400.