Through-wall cabinet - looking for help

I've been asked to design & build a wooden cabinet that will go through a single brick curtain wall. Cutting the hole in the wall is not my problem, other than giving the correct dimensions. The approximate dimensions of the cabinet are 840h x 300w x 140d.

The 'front' of the cabinet will be a framed glass panel, the frame being 60mm wide and ~18 thick. It has to attach to the carcass of the cabinet with no obvious gap, screws or other fasteners. The 'back' of the cabinet is a door on the other side of the wall. The cabinet will protrude through the wall about 18mm, and will have a moulding around it. The door will be attached to the cabinet. It must open to at least 90* and preferably more.

My main problem is coming up with a way to lock the cabinet in the wall without any obvious fasteners. So far, the best I can come up with is to make the cavity a bit larger and have the mouldings on each side extend into the cavity. they could be attached to the bricks. The cabinet can then be screwed to the mouldings and the screws concealed with matching plugs.

Does anyone have any other ideas please. All advice gratefully received.