Some edits I noticed:
As mentioned elsewhere on the board, the early 1970 season shows (1066-1075 or so, can't say for sure) used the previous year's model neighborhood before it was altered slightly (different backdrop with more greenery, the NET building looks a little taller and has a white roof on the new one). During the closing pans of the model, as it approaches the NET building, there's an edit and the remainder of the footage uses the revised neighborhood. From what it looks like on Tim's captures, the 1072 and 1074 copies he has didn't have the trolley episode number card, and didn't have the new NET building footage edit, so I'm guessing this may have been something done to the shows when the 1969-75 repeat package was being prepared.
I think 1101 was also edited for the repackaged post-1976 run. When Fred goes over to Picture-Picture, there's a cut to a tight shot around the frame of Picture-Picture. The wall seems to be a slightly different color in these shots (thought it looks like there were pains taken to make sure it wasn't visible in the shot); I'm guessing they replaced the film footage of the fish because I don't think John Costa was using the synthesizer on the program that early. The fade into the videotaped shot of Fred's fish must also have been replaced footage, then another hard edit back to the original show when Fred's visible on camera again.