I've used yesterday's tractor for parts before, I just got on there and searched and there is a blog on John Deere Van Brunt maybe you could search this blog for a place to buy parts.
I've recently moved its twin out of my barn to my B-I-L's farm. These old drills are the best for planting hayfields and cereal grain- soybeans, not so much. They do require plenty of tillage beforehand to do a good job.
The refurb will be limited to getting it operational and converting it to 3PT hitch. My place is very limited to turning around so i'll need to lift it.
I have one just alittle bit newer than that one and I use it in my lighter soil like a no till.It has a 2 inch ball hitch.I bought alittle bigger one last year that I think would be reall easy to split in half as it has separate controls and would just be moving a wheel and adding 2 spindles then I would have two 5 footers