I'm not sure when the tribute you are looking for was, but I can give you a link to a site where the episode is probably either available or can be requested.
http://coast.gmms.ca/#cgi-bin/forum/YaBB.plI've often wondered about shows predating 1993 myself, as that's the oldest I have been able to track down. According to a piece in the July/August 1997 issue of Skeptical Enquirer Magazine, the beginning of Coast is put at "around 13 years ago", which would place its birth in 84 or 85.
According to Art's Premier Radio biography, the show Art had preceding Coast began in 1985, with the change in format that created C2C coming in 1993.
If the latter is accurate, then I know C2C had to have started before June 20, 1993 as that is the oldest episode I have seen available online.