After the first Marvel Masterworks (Marvel, 1987) series of 27 books, Marvel had Comicraft redesign the look of the books with 'colorful' covers. This set of Comicraft designed hardcover books consisted of 6 reprints (all 'Vol 1') from the original Marvel Masterworks series and 4 new books all of which were printed between November 1997 and Jan 2002. The numbers used for the issues are related to the Volume numbers for the hardcover books used in the later Marvel Masterworks series.
There were only 2 books in this series. The gap is due to the Reprint 'Vol ' and the New 'Vol ' continuing from where the original series left off. There are no missing Volumes between these issues.
These hardcover books can identified by their distinctive covers which had a different background for each character. Spider-Man: Red with a web motif, Avengers: Green with a repeating A in a circle pattern, Daredevil: Red with a Repeating Double D pattern, Fantastic Four: Blue with a repeating 4 in a circle pattern, Thor: Blue with a repeating Hammer in a circle pattern, and X-Men: Yellow with a repeating X in a circle pattern.