Nope - you're spot on.
I've yet to measure WMS to WMS. I believe them to be later model axles and I have the Dana 18 to go with them. They could be out of a Wagoneer, the PO was not terribly sure.
Rear is ~58" WMS to WMS
Front is ~60" WMS to WMS - spring centers are spot on.
Codes off of the tag on the diffs:
Front: C-36970 535239 46-13 354
Rear: " 535693 " "
Here we go - jackpot - wow, these are NOT stamped all that deep and a well-intentioned person could grind them off with a wire wheel if not careful! From the front:
917 6 45
603462 6
Which means:
From a different site..
http://www.jeepgod.net/d44625.html
603462 74-76 Wag & Cherokee 706528x 706135 705110x Disk Brakes ONLY!
Because the tags match and the diff's are both passenger side offset, I'm going to bet that these are both off of the same vehicle

Though there's enough crud on the rear that I can't find the tag

Oh well - given that the other site does not go back that far, it's not a huge loss.