I know, I'm having the same problem. SST is certainly a most interesting case of Hey, It's That Guy! because they seldom credited any of the guest stars, but they're almost always familiar faces, even if the names aren't so much. IIRC, a much earlier episode from the 80s, Miles's grandfather was played by the actor who played Arthur Chaney in the original AIR BUD movie (and I'm pretty sure he also made a cameo in THE MUPPETS (2011), but I can't remember his name. Likewise, I know the guy who played the doctor in the VHS special where Big Bird goes to the hospital played an exterminator in a couple of episodes of SEINFELD. Then, of course, the Retroactive Recognition distinction goes to Giancarlo Esposito for Mickey the camp councelor in the Camp Echo Rock arc.