Ch. 13's first virtual set with the downtown skyline was unveiled sometime during the summer of 1982 and here's an example of it from their 6pm newscast from December 22, 1982:
Dave Ward, Marvin Zindler (RIP), Tim Melton (who subbed in for Bob Allen that night), Ed Brandon and Van Hackett are included in this photograph.
I know ChannelTwoNews has lots of old VHS tapes being uploaded on his YouTube page with news clips, promos, briefs of Ch. 13 during the late 1970s and early 1980s.
If anyone has any more info on Ch. 13's first virtual set from 1982, let me know.