Electric Company Spidey Covers

So I was watching some old clips of The Electric Company on my lunch hour and saw a few spots featuring Spider-Man. As many of you may remember, the "Spidey" stories on Electric Company couched all of his adventures within the context of comic books. The introducing song ran over a clip of someone opening a Spidey comic, the episode itself was framed within a comic book panel, and the series ending with the closing of the comic.

Something I noticed in watching the clips was the artwork used for the covers...
Obviously, these two covers were mocked up specifically for the show (I like how, in that second one, the artist clearly ran out of room on the page and twisted the heck out of Spidey's leg to get it all on the cover) but they should look familiar to long-time fans of Amazing Spider-Man and/or John Romita and Gil Kane...
Now, my question comes up with this next cover, which is obviously a bit more generic and was used for multiple show introductions...
The image looks familiar to me, certainly, but I'm sure part of that comes from regularly having watched The Electric Company in my youth. Was this based on/copied from some general promotional Spider-Man art, or is this a cover that I simply don't see anywhere? I'd be curious to know this image's origins, as well as what other covers were used as visual springboards for the show.

UPDATE: Corrected one cover image and credit, based on Jeff Gutman's comment. Thanks, Jeff!