You can specifically target the about page by page ID in the selector. I’ve used the image you currently have set for the about page. Since that image is quite large in pixel dimensions, I’ve added the background size declaration so that the image will adjust to fit any browser window width.
Thank you very much, I can’t try it now but I will when I get home. The only questions I asked about four or five days ago, and nobody responded. I am not sure if that means nobody knows how to do it, or that simply everyone is busy. Is posting the question again in the forum impolite.