I wonder if every segment has an official title or not. The talk page for The University of Maryland (at Muppet Wiki) has scans from every page of the First Season Show Content, with listings of almost every first season insert, along with a listing of the episodes they appear in Many of the titles sound a bit vague, or more like descriptions. There are some that don't match the titles given in the chapter stops or bonus feature listings for Old School Volume 1 (for example, the page on alphabet skits has a segment listed a s"fishing boy", while Old School Volume 1 just calls it "Alphabet Soup"). Also, the pitch reel has a segment which somebody on-screen referred to as "The J commercial", but the first season show content refers to it as "Sory of J" (unless I'm thinking of the wrong segment, but I didn't see any segments listed as "J Commercial", and these papers also list "Story of D", and there was a very similar segment about the letter D).
It might be good to look at those scans, as a lot of titles listed are a bit vague, and would be great to know more details on. There are a lot of skits that have the word "dump" written by them, which I think means they were no longer shown after the first season. And a lot of season 1 segments are rare (even before the format change of season 33 most of them were rarely shown).
I've seen a still from a first season segment which features Bert, Oscar, and the anything muppets and monsters. The website where I found that picture has a note from the webmaster, saying "I own ten seconds of this skit and I don't know what happens". It would be great if details were found. The First Season Show Content lists something called "Block Party", which sounds like a good match for that picture.
The listing mentions a lot of material I hadn't heard of, such as "Ernie makes a friend", "N-Nincompoop", and "G is for Grover" (could this be the Grover we all know about?). Thanks to Mupet Wiki, if there is a sketch we want Sesame Workshop to send us (if they can), we can check Muppet Wiki for earliest known appearances and mention an episode or two that they appear in. The First Season Shwo Content could be checked for all first season episodes featuring particular sketches, and people can list all of the episode numbers, to be sure that they get what they specifically want.
There are also a lot of sketches that I beleive are rare to us in english, but I think are more commonly available in other languages (or at least some fans have non-english copies). Segments like Windy, and now I forget what else.
It was rumored that Sesame Workshop would sell custom DVDs with up to 10 clips, for 5 dollars each. Would Sesame Workshop sell more custom DVDs to the same people, or just one per person, period, with no exceptions? I guess Sesame Workshop wouldn't send entire episodes.
Of course, I never order things, or participate in tape trades. I don't know if this wil make me change my mind or not. Though I don't do trades, I do occassionally look at tape trading sites, and I've noticed one that included a wish list section, including some speciffic Sesame Street sketches, likie Beat the Time: Grover (though that's just recently been released), Miami Mice: The Count, and Grover the waiter: The Count counts hot dogs. I think that these are rare to collectors. Muppet Wiki doesn't have any images from those segments.