It's tough to find a direct bolt on axle as the early CJ's used an offset housing and from 1972 and up CJ used a center housing.
Early
Dana 44
72 ~
Dana 44
I cannot find a one piece axle kit for this offset diff but I'm not sure you can't convert to a one piece axle and have new longer one made and the other shortened... I'm checking on that...
The closest direct bolt in diff is going to be a
Dana 44 from a 70-71 CJ unfortunately they are rare.
How much fabrication work do you want to do?
The next easiest is going to be find a wide
Dana 44 diff, then your going to have to remove the end plates off, remove the left over tube in the plate, cut the existing tubes to the correct length, remove the spring perches, reweld the ends and perches, then have the axles reworked or buy new ones. Not an easy job but it is doable.
Other then that, a new axle and hub in US$ is about $110 ~ $117 depending on the spline count. Most Jeep replacement parts sites sell them. -->>
http://www.jeep4x4center.com/jeep-axle-differential-parts/dana44-rear-cj-willys.htm