From my (little) knowledge, Ashmont where the IP in question is located is slightly worse than either of those 2 Beanie Girl. From my understanding, Kooringal is slightly better than Mount Austin but there isn't a huge difference in it.
You mention that the lease is about to finish (next week - so I assume 19 May 14 or so) but you want to turf them out??? Why not just wait until the lease finishes and give them their marching orders. I assume you will also be renewing your insurance until all this is finished and the house sold...