Be very studious about changing anti freeze. This tractor has a tendency for blowing head gaskets if engine is run hot. Had mine for 28 years. Minor parts are easy to get. Its the major parts that show NLA's. A good parts manager will help you a lot. I once had a float valve go off the fel control. It is sold as one piece and "non-reconstructable". It too was deemed "NLA". Only part broken was a tiny spring smaller than a snot. I would have had to buy the entire scv for $700. A smart parts guy found what looked to be the same spring in 318 garden tractor control. He ordered it, and it was the same spring. Cost me $2.32 and indeed was reconstructible. I worked my 750 to the bone but as things started letting go, it was time for a new tractor. If it is used lightly and fluids changed regularly, this should last you for a long time.
This one (yours) looks like it had an easy life, always covered and in great shape. An exceptional find.
Here's a pic of mine dealing with some stuff not much seen in Missouri I bet.
All the wood stems you see in the back ground (actually you can't see them very well) was dragged in by this tractor. 28 years worth of skidding in large stems.