Keeping with the Letterman in the seventies theme, here's David on two separate episodes of Dick Clark's $20,000 Pyramid. Two segments from episodes in 1978 and 1979. On the first clip we see him once again with all-purpose celebrity game show contestant Joanne Worley. Check the comments section for helpful details courtesy a friendly reader.
Another clip from a different episode, notice David's striking resemblance to Quentin Tarantino: