I hope your next birthday is soon. Next advice is to machine some jewellery. I scored high with titanium earrings. Things you need before your next birthday, and this is my personal opinion: cutting tools, you can't cut without them, centre drill and some drills, some taps, countersink and a chuck. A rolling centre is nice for long(er) things, but not in the emergency kit. The same for moving rest and dead centre. Measuring equipment, including the dial indicator, ranging from basic to total bankrupcy is also handy.
With a little fantasy a 4-jaw chuck, a little larger than your 3-jaw, can bring you half way into the milling department. It would be on top of my wishlist. I bought it before my quick change tool post. Buy the boring bars in size as you need them. A moving rest and a knurling tool fall in the category "buy if needed", they collect dust most off the time.
I wish you and SWMBO a lot of fun with the fullfillment of a half lifetime wish.