I was thinking, if the OP has children then my opinion would be to keep it for a number of reasons. Firstly the jacket has a direct link to Apple (label inside the jacket proves this), then there is the link between Apple and the childrens grandfather and how he came about to getting the jacket. If the OP does have children, it would be nice one day to say 'Here kids, here is a bit of Apple history that belonged to your grandfather'. Something like that is priceless.