they exist in paper form at Manx museum where film EW1 cover 1600-1612, EW2 1612-1619 ...
they were done from 1990 onwards mostly by the late Les Quilliam and others
The format is described
This index is made up of a Page Number,
the name of the Testator or Testatrix and the Parish
in which the Will or Administration are recorded, in the order in which they appear on the film.
Women, whose maiden and married names can both be determined, are listed with nee, or where the former is not apparent, with alias. Spellings are as found and may not be consistent with modern usage. Damage to the pages of the Will Books recorded on this film sometimes makes it difficult to determine the navies of the Testators and the Parishes where the wills are recorded. A little detective work may then be necessary, including reference to Defuncts Lists, which occur at intervals throughout the Will Books.
In the Card Index built up from information contained in the Wills, imprecise dates are recorded with c, meaning 'about'.
A page refers to a double page of the record book, opened out flat.

the 1st 4 entries on EW1 are:
001 GAWEN Christian GN?
002 McFREERE John GN?
006 KISSAGE William BH
006 ILREA Christian BH
008 MclLREA John BH

parish names are 2letter abbrevs

The Card index based on names within wills is on handwritten cards if memory serves but using a preprinted template