If an item is deleted (anyone with write authority can delete an item), then a new item with the same name can be created.
Viewing the item history by name shows the prior versions of the item with a revert link for each revision. However, if any one of these revert links is clicked, the eventual result is the message "Item(s) named <name> already exist."
This is an error, the revert should work (or the revert link should not be present).
A workaround is to click the highlight link of the desired revision on the item history view, copy the data from the highlight view, edit (modify) the item, paste the copied data, and save.
In contrast, if the deleted item can be found in the view of Global History (may be difficult if the delete happened long ago or there are many deletes), and the link to item-id history is clicked, then the revert link by item id works.