You can look at the index up to 1949 on LDS film no. 0106366 at their Family History Centres worldwide (see phone book under Church of Jesus Christ of Latter-Day Saints). The last section of the index 1921-1949 is indexed by year, and includes profession and address, which makes it very easy to search compared to the earlier wills/decrees which are listed by parish (and why Brian started his index). The wills themselves on film end in 1916, so when found you would need to email the Registry to buy a copy. See "Contacts" at www.gov.im/registries/general/civilregistry/
If you can't get to a FHC the Registry used to do an index search for a small fee.

Sue