The 1-piece axle doesn't need the seal on the brake side of the CAD, because you need to install a seal on the inside of the carrier same as the driver's side. The axle shaft itself isn't machined to ride on a seal where the stock seal is located.
As far as the bearing/bushing on the diff side of the CAD, I left mine in there. It isn't required for anything, and the axle fit into it. So I figured why bother?
'87 YJ, 4.2L built and bored, 8" of lift, 8.8 rear, AX15/NP 231J, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...