If the pellets are something he wouldn't buy himself, then IMO they are present-worthy. From the sound of your post you'll both have everything you need, and looking for things to buy is unnecessary (again IMO). I think a present should be a treat - either something the recipient thinks is too extravagant to buy (it doesn't matter whether it is a fancy car or a bar of luxury chocolate) or an upgraded version of something they usually get for themselves. Either way, the best presents are not generic anythings, but gifts bought with love and thought.
I would never think to get anyone lion pellets, but I've never met anyone who would want them😂. I think they would make a much better gift than a jumper or shirt to live in his wardrobe - particularly so as this is an anniversary and it will show that you know him better than anyone else.
Have a lovely day, and I'd love to see your brooch if sharing a photo wouldn't be too 'outing'.