This is why it is best to keep all your posts on one subject in one thread.
My father died in June and my Grandmother had a small insurance policy for him. The beneficiary is my Grandfather who died several years before...
Let's see if the facts are correct:
Your Grandmother was the policy owner.
Your Father was the insured.
Your Grandfather was the beneficiary.
Is that right?
If it is, I don't see how the proceeds would be paid to your father's estate. The insured does not become the beneficiary because the designated policy beneficiary passes away.