Let's see...there was Anne Meara. Although she did more of course, her appearances on HSq, PW+, BtB, & Pyramid qualify her.
Jo Anne Worley appeared on HSq, IGaS, Pyramid, and Hot Potato.
Finally for now, a less obvious entry would be Anson Williams. He guested on Magnificent Marble Machine, Match Game, BtB, & $10,000 Pyramid.
EDIT: There was one more I intended to note, yet for forgot to do so: Jayne Meadows. (Celebrity Game, IGaS, $10K Pyramid, & Hot Potato)
I too would've jumped and said Nipsey, but it appears the only other H-Q shows he could have possibly done are MMM, People Will Talk, or Baffle.
Wouldn't Ralph Andrews Productions also be considered one of the big companies of that time period as well? That company is responsible for a slew of celebrity-driven games.
Not that I'm trying to pad the Nipsey Russell count...
--Jamie