Sounds like a nice starting point, maybe a good candidate for interior swap from a northern car with less sun exposure but some rust. I did that one time and it worked out well -- had a 740 wagon from Maine that had pretty serious body rot but a beautiful black leather interior. I swapped its carpets and seats into another wagon that had good mechanicals and sheetmetal but a tired and sun-baked interior. Turned out very nicely, combines the best of both scenarios. Sounds like if someone did that, then for not much money and a little work they would have a cherry low-mile 740 TD from a dry climate.
Good luck with the sale and hope it stays with a good owner. Photos would probably help the sale, and you can add them on here for free, so perhaps be good to consider doing that.
Also, any history you have regarding the most recent front timing belt/water pump/idler bearing replacement is a good thing to note proactively, since it will be the very first question any knowledge buyer asks about (the second question will be if it has ever been overheated or had a headgasket replaced, so may as well mention that too
).