Garcia, Jerry, 1942-1995, "Ben Fong-Torres interviews Jerry Garcia. Interview recorded circa 1975 for the documentary radio program "What was that?" broadcast on KSAN-FM in San Francisco [radio broadcast]," Grateful Dead Archive Online, accessed November 10, 2013, http://www.gdao.org/items/show/379555.
The interview is given as 1975, at least some of it takes
place at His Master's Wheels, and there's a snippet with Nicky Hopkins. I have
Jerry and Nicky et al. there working
on what would become Reflections
mostly in September-October 1975, so this seems the most likely timeframe.
Sketchy notes below the fold.