I am sorry for your father's health troubles. It is a blessing that he has had so many years of good health but from your description he is certainly in difficulty now. Unfortunately, I am aware of no surgery to restore his ability to swallow if that has been paralysed. Once lost, nerves cannot
regrow, either by doctors efforts or by nature. However, sometimes the undamaged nerves learn to take over the function of the lost nerves and paralysis improves over time. There is a real possibility that your fathers swallowing and breathing will improve with time (usually many months) if his other troubles can be controlled. It sounds as if you have excellent doctors and that you can trust in their abilities. I wish you and your father well.