It is interesting that some of the reportedly lost episodes are at the AAPB now. I wonder if the museum managed to get copies or if Sesame Workshop ended up finding copies/having them after all (like with episode 1814 which was reportedly lost but assumed to be a database error). I've seen a few screenshots of these lost ones and it seems the copies are all in black and white. For a while I had wondered if maybe the workshop did actually have copies of those but they just weren't of the right quality for broadcast or an official release (like maybe an episode being mostly incomplete). The fact that these seem to be in black and white could indicate that, but the wiki screengrabbed a few episodes that they got in black and white that were not reported to be lost.
I wonder about whether the "Lost episodes of Sesame Street" page should have something about episodes that were previously reported as lost. I don't suppose anyone knows how they managed to get some "lost" episodes there (well, maybe somebody could ask the archive).
I had seen a few guides get one new screengrab (not from any of the users who had been getting rare episodes.... are they still getting episodes?) and wondered how they got them (I clicked "what links here" on one image to see if maybe that scene was used in another episode or in a guide for a foreign dub, but didn't see anything). This was just before I knew the AAPB got seasons 1-14, so they probably just screengrabed the main episode images on the website.
and I guess if anybody here goes to the AAPB, it would probably be best to view one of the formerly reported to be “lost” episodes and see if the show content matches up with what the wiki has.