3
Stack Exchange Data Explorer might at least help; you can search posts by the deleted owner's display name.
Posts by deleted owner's display name
SELECT Id AS [Post Link], Score, Body
FROM Posts
WHERE PostTypeId <=2 AND OwnerUserId IS NULL AND OwnerDisplayName = '##DisplayName##'
ORDER BY CreationDate ASC
(not tested thoroughly, might be buggy)
Only top voted, non community-wiki answers of a minimum length are eligible