Great article and imagination, about all I would suggest is toward the end of the trigger ...

FROM

WHERE Content IS NOT NULL

AND ( v.itemID IS NULL

OR v.modifiedDate != c.ModifiedDate

) )

TOWHERE Content IS NOT NULL

AND ( v.itemID IS NULL

OR v.modifiedDate < c.ModifiedDate

) )

this way it is just not equal in modified dates to the latest history version, but that you are not re-importing any past previous version.