Hey Stew,Went out and looked this morning and right now it is covered in snow and the wind is up so it may be a day or two before I get a chance to get measurements.
I don't believe that anyone makes the six spline yoke new anymore - I talked to a chap at Neapco several years ago and the way he spoke they supplied the yoke originally but obsoleted it in the late 1990's. They are still available used and worst comes to worst the spline can be cut and placed inside another yoke. This article shows how I repaired an old one that the splines were worn on and the insert I made could just as easily have been placed in side a new yoke that had the inside turned to the correct O.D.
I found that link yesterday searching for someone who I remember had repaired some splines. As it turns out, it was you! Couldn't log in from my phone to thank you for the efforts you put to document everything you do. Although after looking through it, I soon realized at the moment, that is out of my reach too. I don't own, have access to or know how to operate a lathe but I did download it for future use. Ill keep looking for a work around or buying a used one on ebay for now.
And thanks again for taking the time to help me out. No rush on the drive shaft if the conditions are not favorable. Gives me some time to slowly collect the other parts needed.