Nice purchase, congrats. I would wear it much the same as a navy blazer honestly. As you will be wearing it in colder months, just be sure to wear appropriate fabrics for the cold and you should be all set. Grey flannels and some brown brogue boots sounds nice. Or maybe some green moleskin trousers with some chukkas. If there’s enough room you could also layer it with a dope gilet or cardigan, for extra toastiness.