Regardless of the year, you've got a perfect real keeper!
Here are the Stumpjumper-related pages from Specialized catalogs:
-
1990 Specialized catalog, page 8
-
1991 Specialized catalog, page 29
-
1992 Specialized catalog, page 46
It can't be 1992 as the catalog shows only 'yellow' and 'metallic purple' available colors.
It can't be 1990 because that year
Specialized logo font looked like this.
Your bike is the 1991 Stumpjumper. It is peculiar that 1991 catalog doesn't have 'Tange' listed in the specs; however, it is shown on your bike's seatpost decal.