Giv, that is such a wonderful baby blanket! You need to keep it for when one of your granddaughters is a new mother. Taste in quilting seems to skip a generation, so it may be just her 'thing' when she has her own baby. Just like our daughters wouldn't be caught dead wearing our out-of-style wedding gowns, but our granddaughters want them!
There are products that get the yellowing and stains out of vintage fabrics without damaging them. I think the one I'm thinking of is called "Restore". You just soak the piece in Restore and it comes out clean.