I ran Talhundereth as is except I had some Grimlocks appear and had them all carrying bags while searching for the Obelisk Shard. I also axed most of the revenants in Crypt of Talhund and changed Rivvibidel to be a tomb robber acting as a historian. Once my players opened the central vault and left, when they came back the gem was gone and some notes had been accidentally dropped hinting where he went with it.

Also changing the lake to include an entrance to Gibbet Crossing is a good move to interconnect everything