Post-64 push-button type with two studs, shaped gaskets go between the ends of the handle and the paint-work:

There is a return spring on the shaft of the button, and a screw, lock-nut and washer to keep the button in the main part of the handle:

The screw is fitted to the button shaft then the nut is turned down to butt itself and the washer up to the end of the button shaft, which positions the released button correctly in the main part of the handle. The screw is then set to operate the latch correctly, and the lock-nut tightened. Lubricate at the points indicated here ...

... which can be accessed using a spray or can with a nozzle just by removing the waist-rail as here (picture taken for the lock hence the handle is a bit out of focus):