Hi Chris,
As far as I am aware TF-FIB is still current as 4CC2C4. My database has it flying in the Australia region in the last week or so and it is noted as possibly changing to P2-PXW.
If you have it have noted it with the 89805E hex and Icelandair flight ID combination this could possibly suggest a delivery flight under the P2-PXW registration.
Alan