Missing statements and information

My grandfather left everything to his second wife. When she died 10 years later, she left half to her son and half to my grandfather’s three children. All have deceased. I found there were royalties waiting to be distributed under my grandfather’s name. I obtained all legal documents and filed on behalf of my cousins. I found there were years of royalties that are unaccounted for. The wives did not probate his mother’s will, and it is believed he received the royalties until his death. I cannot trace this money back. I do not know whom to contact. Oleze of Illinois is the producer, I believe, and no one in the company will call me back. Where can I find this information? Also, I understand one well is dry. I would like to find out if anything has been done to revive it. Can anyone help?