As a veteran, there is no ethical issue with this, stipulation being that you purchase/acquire decorations that he has earned. I made a shadow box for my FIL and bought new decs for it. It is the act that was performed for the medal that is meaningful, the medal itself not so much, IMO. Often, in today’s military, the medal that is pinned on in ceremony is reused. With the exception of a few, medals are rather meaningless, and are glamorized by film.