Good news. I've been looking for these parts too and couldn't find anything.
In the third pic, how wide would that part be? It looks to be about the same as the blades of the aurora m8. If it's the fenders and front/back end of a vehicle, what scale might it be?
So far, the only military vehicle I have looked at that might have fenders like that is an elefant tank, but every kit I've looked at has the fenders as a separate piece. This piece seems to be all one, from one side of the vehicle to the other. That is, if it is fenders of a vehicle. Who knows?
Could it be from a farm tractor? Like AMT?