My new driveshaft just arrived. I verified that it is the new part number that Grumpy identified for us. Interestingly, it has 22 splines at the front end and 20 at the rear. I can only assume (and hope) that the original shaft is the same. Manufacture date is 02.03.23 (March 2, 2023). The space between the large diameter (~2 inches) casing of the front half and the smaller diameter (~1 inch) shaft of the rear half is filled with a high density rubber-like compound. I can't remember whether the same is true of the original.
Given the history of my current (original) driveshaft, I intend to swap it out for this new one sometime soon.
Given the history of my current (original) driveshaft, I intend to swap it out for this new one sometime soon.