Wow! I've been on this site since 2013 and never once have I seen a reference to one. Must be rare. Nice find!
P.S. Just did a site search for this and got one hit - your post!
P.P.S. Of the two readable satellites on the label, Westar III, was launched in August 1979 and Satcom IV was launched in January 1982 so it puts it after 1982 but I'd bet not far after!
https://www.n2yo.com/satellite/?s=11484https://www.n2yo.com/satellite/?s=13035