Here is the view for the cassette side showing the Campagnolo Chorus 11 speed rear changer on its fabricated hanger.
A closer look. The welding of the alloy framework shows very neat and competent workmanship.
A square-on view of the differential housing. Presumably the large splines are to aid dismantling.
It can be seen that the alloy framework welding is very neatly done and the fillets generous.
The disk brake rotor is attached on the right to the differential housing to provide equal braking to both axles. Rear braking is always subject to adhesion limits on a lightly loaded trikes.
A better view of the rotor disk. Its large diameter sets the clearance required for the rear axle housing reinforcement tubes.
Where disk brakes are fitted to the rear of British trikes they have usually been duplicated to provide balanced braking on one brake lever.
Though some vintage trikes had rear drum brakes. Sometimes a single at the centre of a differential model. Or one for each wheel fixed out at the rear hubs.