As stated in the [url=https://www.bungie.net/en/Forums/Post/216505548?sort=0&page=0]Festival of the Lost Vital Information Thread[/url]: [quote][b]Holiday Item Collection[/b] At the launch of 2.4.1, the Masks available to be reacquired through the Holiday Item Collection were based on the Masks that a player had in their Inventory or Vault. [u]If a Mask was deleted prior to this (the release of Patch 2.4.1.), that Mask will not be available to reacquire through the Collection[/u] until the player receives the Mask again through gameplay or purchase of a Treasure of the Lost from the Eververse Trading Co. store. For more information, please see our Item Collections Guide.[/quote] Unfortunately, Bungie cannot provide services to restore deleted or otherwise lost items.