To delete only a specific version:

1. delete the whole page, noting in the edit summary that it's a temporary deletion
2. click on undelete
3. click on the first version
4. shift-click on the version right above the version to be deleted  (this will highlight a whole string of versions)
5. similarly, click on the version below the one to be deleted, then shift click on the last version
...  

BE SURE to keep deleted versions that are already deleted.