Congratulations on your new place.
Yes, I believe you are moving in the right direction. If your available money is limited, it will buy more in a tractor that is a little too large than one of the popular CUTs right now. I've tried both routes and ended up with several of each style....that was originally due to poverty, but eventually as much out of tractor curiosity as for any other reason. Lots of excellent old US-made tractors are selling right now for what is barely more than scrap value. Many have matching implements for similar good values. Those things were built to last! Real American Art. There are lots of good ones out there, and the farmers that have them tend to consider hauling machinery around as just part of a day's work. Do keep in mind the mechanical philosophy of the time does affect the older machines. Fifty years ago, tractors were surprisingly modern in features and rather astonishingly dependable overall, but they were also designed for more owner tinkering and adjusting than is popular today. To enjoy one, your mindset should be able to turn in that direction. I will say that in these old tractors I very much prefer and recommend one having a worn gasoline engine over the diesel versions.
Our old JD530 is a typical example:That gas tractor is over 50 years old and cost us only a little more than a riding lawn mower ($2000) - mostly because it had newish back tires! When we found it, it was being used as a stationary water pump in a farmer's field. But he unhooked it, put it in gear, and it drove right off. It came with power steering, a massive three point hitch, hydraulic power in every direction, the original tools and manual, and a comfortable sprung and damped operator's platform sorely needing upholstery. When we got it that tractor it needed adjustment, lubrication, and attention in every single system.....but no real $$ repairs. Everything still worked, and in fact it still does. I'd wanted one with a front loader, but found we couldn't afford it. It turns out that many old tractors used something called a 3pt bucket....now few people use them but they still work fine. Not as handy as a front loader, but for a few hundred dollars ours would lift and carry a ton of anything. A tractor that size will run just about any normal implement - and implements are everywhere. Eventually we found an old factory loader in a field and bought it on the spot for almost zero dollars. Not surprisingly, the market in old factory loaders for full-sized tractors is similarly depressed. They only fit a big old heavy tractor and really won't fit anything else.
BTW, if you need to reduce the impact of the heavy tractor on your soil there are quite a variety of less-aggressive and wider tires available today. And to my surprise there was even an active local market in used tractor tires. Tractor tires last decades. Old tractors have traction to spare anyway.
I know more that might be helpful about old tractors in general, but don't know much about the AC D17 in particular. That model spanned some years. Can you post some pictures and give some specific info? Pay attention to the rubber, engine/transmission, 3 pt hitch, and of course the hour meter and instruments.
good luck,
rScotty