"Starting in March 1945, a new single-link Kgs 73/800/152 track was introduced that was again driven by an 18 tooth drive sprocket." - Germany's Tiger Tanks VK 45.02 to Tiger II, Jentz and Doyle, page 70.
This was the final track type. That said, several photos show final production models factory fitted with transport tracks and 18 tooth sprockets, such as the so-called "Octopus Tiger". There was obviously a shortage of combat tracks, as evident by the use of transport tracks on numerous vehicles. The use of the Kgs 73/800/152 track appears to have been rather limited, possibly only the last 30 vehicles or so, plus the test vehicles of the sPzAbt 506 and SSsPzAbt 501 used in the BoB. The situation becomes more muddled the further we inquire. It is possible that both track types were used until stocks of the double-link tracks and 9 tooth sprockets were depleted.
Here is some further discussion of 9 tooth vs 18 tooth sprockets being used on final production vehicles and descriptions of the 4 track types. 2/3 down this page, the different track types are described, as well as other features;
http://www.network54.com/Forum/47207/thread/1358002754/Dragon+Last+Production+KingTiger+kit
I haven't come to a conclusion over all of this, as it requires matching scarce, blurry photos to chassis numbers and then trying to reconcile this to available production data....I'll leave that to someone else. The fact that completed turrets found at the end of the war at the Henschel factory had welded on track hangers for the double-link track, along with turrets at the Wegmann turret production plant with single-link track hangers, suggests that both track types were in use until the end of the war....or were the older-style turrets simply stockpiled at the Henschel final assembly plant....Does anyone have actual production data to support either situation? I don't know. 
I'm sure there are other discussions on this "can of worms" elsewhere... 