Additional footage from the cartoon «2 stupid dogs»

Something I have never seen, but I have read from different people on the Anime Superhero (nee Toon Zone) forums and in the Facebook group of the Cartoon Research website is that there's some stuff from the Hanna-Barbera show «2 stupid dogs» (1993-1995) that only aired on the first run (either on TBS or syndication) and hasn't rerun from 1994 onwards, like:

• A different opening with a doo-wop style song.
• Additional bumpers featuring Hollywood (the guy that yells «BUT IT'S WRONG!»). Current reruns only have one.
  
• A mail address mentioned in the credits asking for feedback about the show (? ? ?).

Anyone has more info? What I have read on the mentioned sites is no much longer than what I said.