R.I.P., Peter Mark Richman.
Richman played Dr. Klaus Bergstrom in Goliath Returns in S2, and Kleist in S4's Many Happy Returns. I liked Dr. Bergstrom and that's one of my favorite guest star appearances. (Though my mother and I both agree his 'Swedish' accent sounded more like German.) ;)
He was also known for playing Chrissy Snow's father, Reverend Luther Snow, on Three's Company, and had many other film and TV credits.