He added the last name Ponyman to his in the 1970s, as an expression of his playful nature (per Nurit Tilles' biographical sketch of Kuhner at The Estate Project. 
While in San Francisco he became a well known actor at such venues as Theatre Rhinoceros and 544 Natoma. "He created the mysterious Leatherman character in the premiere of C.D. Arnold's play Delivery, and appeared at 544 Natoma in Cal Yeoman's Sunsets, among numerous other shows. He was also active in San Francisco as a "sporting club host" at the Caldron and Bootcamp."
Six months before his death he performed an evening-length autobiographical one-man show called Sawdust, consisting of 26 songs he had written over 15 years.