I emailed Clarke Buehling from the article above and he gave me the following response:

"Jim passed away around 1972 or 73, I think, of kidney
problems.
I was going to the San Francisco Art Institute at that time,
and would often hitch-hike to Berkeley to socialize with the
Humbead band. You know that Sue Draheim much later moved
to Berea, KY where she passed away a few years ago.

Karen Guth was Jim's common-law wife, you could say, but
I have no idea what became of her."

From that info, I've found an obit for a James W. Bamford (age 34) whose funeral was on Dec. 2 1973 of "nephrosis and a stroke... in Berkeley after a long illness" (source) - no mention of Karen, though.