Workman's Compensation Help?

My husband was recently hurt at his job. He fell and landed on metal, the metal pierced his dominant hand and cut the nerve. He had surgery to try to repair the nerve to regain some feeling in his fingers. The doctor said that he will not get full feeling back, but they wont know for six months. The Workman's comp insurance paid him 70% for the time he was off for the surgery. They also said they will pay him for the mileage. Is that all we will receive? Is it common to offer a settlement after he is released? If so, is there a calculator or something to go by? We want to try and refrain from hiring an attorney, but we don't want to settle for less than he deserves. Any help with the process or the amount or if you have had something similar ....any feedback would be greatly appreciated. I should mention he lives and works in Oklahoma. Thanks in advance for your help!