Brian's Burial Index is a brilliant resource as are his Will and Census Indexes and his embryoinic marriage index, but he can't add burials and cremations if he does not have the information through non-publication, loss or whatever.

If you are missing an end-of-life record, the Manx Museum holds an index of the Civil Registration (including deaths) in the Isle of Man on microfiche using which certificates can be bought from the Registries in Douglas - it will be a few more decades until such information is available via the WWW unless Tynwald funds a digitisation project - sometimes we have to go back to the original records.