Newton Comics published 17 issues of The Amazing Spider-Man. The final issue was cover-dated March 1976. A Newton Spectacular edition of The Amazing Spider-Man was published in December 1976:
The cover image originally appeared on the cover of Marvel's The Amazing Spider-Man #128:
This image had been previously published by Newton as a poster in The Invincible Iron Man #2 and Daredevil #2, both cover-dated March 1976:
Newton Comics was not the only publisher to deem this image worthy of promotional duties. It was adapted for the cover of Gemstone's Comic Book Marketplace #67:
The contents of this issue are as follows:
The Man Called Electro!, previously published in The Amazing Spider-Man #10
The Return of The Vulture, previously published in The Amazing Spider-Man #6
Have Yourself a Sandman Little Christmas!, previously published in The Amazing Spider-Man #2
The Wondrous World of Dr. Strange!, previously published in The Amazing Spider-Man #5
Where Walk the Villains!, originally published in Tales of Suspense #67, July 1965
All four Spider-Man stories had been previously published by Newton in the regular series. However, they did vary from their previous iterations.
For example, this is the final panel of the story The Return of The Vulture as it appears in Newton's The Amazing Spider-Man #6:
This is the same panel as it appears in Newton Spectacular:
The caption box has been omitted in Newton Spectacular, and the art extended in its absence.
There are other differences between the first and second Newton printings. For example, the Sandman story in Newton Spectacular is missing the 13th page; the splash page is uncropped; the job number is omitted; and the Team-Up 1 printer's markup from The Amazing Spider-Man (Newton) #2 has been erased.
There are other such differences between the two printings but the ones above are the most obvious and noteworthy.
The Spider-Man stories were recycled but the Iron Man story made its first Newton Comics appearance in this issue. (As I have not indexed every Newton issue yet I leave open the possibility that this story lurks in another issue - but I have not come across it.)
Spider-Man would appear in other Newton comics, and indeed would be cover-featured on a few, but this was the only issue after the end of the ongoing series to feature The Amazing Spider-Man masthead on its own, the Newton Spectacular title notwithstanding.