Just to add my own half-cent's worth to the discussion based on my studies of the set over the years... I'm going to have to disagree with you on that... I've noticed throughout the 80s, various elements of the set seemed to be slightly spruced up over that decade, like for example... 1. Big Bird's doors were repainted during the mid 80s, even though they had the same pre-1993 color scheme (dark red, dirty green, pale grayish blue, and brown, opposed to pale red, minty green, turquoise, and orange), they didn't look quite as weathered and such. 2. The carriage house/garage looked a less weathered, as did 123 by the mid 80s; and as ssetta pointed out, those number "stickers" over the garage doors kept pealing off over this period of time. 3. The backdrop of the brick wall behind Big Bird's nest with the alphabet and number paneling and such was repainted, making it look a little brighter, and I think it was painted at a smaller perspective, as we could now see more of the paneling, that was once concealed by the small fence. This was by the late 80s. I honestly believe the reason the backdrop looks to be going uphill is because of the angle we're used to seeing it on screen... I bet if you were to look directly at that particular backdrop from, say, right in front of Hooper's, the perspective would be more realistic, in making the street look longer than it really is. But one thing I have noticed, and wonder if anyone else has, is that it seems like during the years when the set was assembled in the Teletape studios, that maybe the studio floor wasn't completely level, because past 123, it seems like everything does kind lean a little bit like it's going up a hill... I mean, don't Big Bird's doors and such during that period look like they lean to the left? You're absolutely right, and it's the same with the tree in front of the tenement building that houses Hooper's and the Fix-It-Shop, though I've noticed that tree seems to disappear more than the one in front of Oscar's can. Yes, from 1970 to 1987, the backdrop had two distant apartment buildings, with maybe a smaller building wedged between them, with nothing but a patch of blue sky inbetween them, and the alphabet factory wall... though early in the 70s, there was a group of palmtrees painted on the patch of sky, I guess to give the small bit of foliage in that part a fuller feel, because afterwards, the painted trees disappeared, and we always had a couple of sad looking palm trees dangling over the fence (and this backdrop was originally behind Big Bird's doors on the straight 1969 set). But yeah, by 1988, the buildings were changed: there were three different buildings in a row, and I guess to give it more depth, they added the top of a skyscraper behind them, but we still had that patch of blue sky, until the very early 90s where the additional buildings were added, filling up that once empty space, which I agree, did add more realism. Now one thing I would like to bring up, that I'm surprised no one else has... everybody has been complaining about the sacrifice of the fire escape on the side of 123, but I can't believe that no one has mentioned the tire swing... the tire swing had been a fixture all throughout the 70s, 80s, and 90s, but during the 2000s, it had pretty much been phased out. In fact, by 2002, it was completely gone, except for maybe an occasion or two where we would see a little kid actually swinging on it, but other than that.