In the episode "Gracie Adopts a Great Dane" there are two scenes when Harry Morton performs acrobatics....one where he jumps out the window and once when he falls down the stairs, both times running from the dog. Is he that capable of this or did they have stand in stuntmen in those days?

I'm gonna take a wild guess and assume they used a stunt double... Larry Keating doesn't strike me as the flexible type ;)

I saw an episode today where Harry von Zell takes a tumble showing Ronnie judo. Harry flew behind a couch so a stuntman might flown through the air and waiting behind the couch was the real Harry.