I had a similar hunt for a missing local ad. Your best bet is to contact the TV station directly and explain your interest. Sometimes smaller stations are willing to dig stuff up from their archives. Also, local historical societies can be a goldmine.

What you'll want to do is expand your search to not just English-speaking sources. Sometimes these obscure shows were bigger in other countries and you might find foreign dubs or subtitled episodes. Websites dedicated to lost media can be a treasure trove, but don't overlook smaller, niche archives. Persistence is …