Could it be that it is Mr. Neave's age what makes him so lonely, or it is also his wife and family the responsibles of his loneliness?
It seems that his wife doesn't feel like him, she doesn't seem to be a good companion of him, or it is what Mr. Neave feels.
I think all of us, at one time or another, feels lonely. Even in the best of marriages a man still needs the companionship of other men, and women need the companionship of other women. Perhaps that's the source of Mr. Neaves's loneliness. Perhaps if he had male friends his age and socialized with them from time to time he would appreciate his family more. Perhaps if his wife and children socialized with friends their own age and gender occasionally, they would treat him better.
I'm married to an older man. There's fourteen years difference in our ages. However, I appreciate his wisdom, experience, foresight, and the fact that he was well-seasoned and settled down when I married him. I love and respect him very much and can't imagine ever using his age against him! But, we both need our space and our alone times to think, regenerate, and regroup. I think we both get lonely for our own gender at times. He goes out to the lunch with his brothers and sons; I go out to lunch with my mother and sisters.
Loneliness is of course an excellent theme of this great short story. However, it appears that the loneliness of Mr. Neave is mostly to do with his age. He is isolated by his tiredness, and the way that the rest of his family treat him. Also, there is a real sense that he is somewhat patronised by his daughters, wife and son. Notice how the story starts with Mr. Neave insisting that his son is not ready to take over the business.
When analysing the short story it might be worth examining or researching the differing approaches to ageing in various societies. In many eastern societies, the elderly are respected, even revered, for their age. Age is considered a bringer of valuable wisdom. This might give you some very interesting insights and angles for your study. How do the family's attitudes measure up to these views?