OK, I have been some searching on the difference.
The way I understand it, if the axle has one end with 5 or 6 bolts around the flange next to the differntial, then it is the Annular type axle.
The Homokinetic axle have a can on both ends and no visable bolts.
the Homo axles are the original axles these cars came with, then around 1986 the Annular axles were introduced.
with both type of axles the Diff. cover has to be removed to install them.
But with the Annular axles the cover does not have to be removed the
next time the axle has to be replaced. just remove the bolts on the
flange.
Also doing my axle search, the two axles can be used together on either side. so you can mix and match
I not real clear if the 126 and 123 axles can be used either way. from what I searched maybe the earlier 126 can be used.
Charlie