I'm also trying to follow.

"My client reaquired the property subjected to a complete step up in basis as far as I understand"

You can't reacquire something you already owned. If it was her property and he was given "right to live there and operate it" then she still owned it. You don't inherit it because it was yours all along.

Was the property bifurcated? You mention 50 acres and also 162 acres.

How much longer is that production lease? If there is a lessee, wouldn't they have the production history? How would that die with the brother? Are there no records, not even filed with the County or State Ag?

It seems maybe the brother did the tax reporting on the property and not your client?

Once you get that clarity, it might help to know exactly what you are trying to solve for.