Ok, so now I have this query

	SELECT LH.* 
		FROM LocationHistory LH 
		INNER JOIN (SELECT MAX(Sequence) AS Sequence, PartID, SerialNo 
			FROM LocationHistory  
			GROUP BY PartID, SerialNo ) Derived 
				ON LH.Sequence = Derived.Sequence and 
				   LH.PartID = Derived.PartID and 
				   LH.SerialNo = Derived.SerialNo

I want to include as part of the result set a count of all records of each PartId/SerialNo combination