its t18 rear and adm ae86 front for t50 to T series rear.
these 2 parts are joined by a flange and 4 bolts.
your 71 shaft is not really meant to come apart, except to maybe get serviced (eg new unis) theyre aus made too and so its not really a surprise they use different uni joints.
the unis on the t18/86 shaft are staked also, and are non service able.