The story of the Pig is hilarious! I always thought it was air brushed in...😂
My art framer of many years did work only for museums, galleries, and a few collectors he liked. One day I was dropping off a piece; we would normally work collaboratively on how to frame it, and he would often show me some outrageously expensive or rare thing he was working on for someone else...
He told me to come look at what he was working on. It was the "original" (i.e. darkroom-merged photos by the photographer) photo used to create the Animals album cover. As usual, I did not ask who the owner of the original photo was, and he did not volunteer. But it was very cool in real life, and of course much larger in size than an album cover...