Having watched some of the news update briefs from Ch. 13 back in the 80s, here's some other versions of other news stations across the country, who used virtual sets during the 80s: WTVD-TV Raleigh, NC from 1988 (Clare Casademont)
WTVD-TV open & close in 1991
WTVD-TV on March 3, 1991
July 1, 1987:
KABC-TV 1988 11pm News Open http://www.youtube.com/watch?v=CC9Z6Na75ig KOMO-TV Seattle from December 11, 1983
KOMO-TV's July 4, 1986