Interior shell with 5" insulation space.
There will be two of these folding side panels with triangles mounted with piano hinges.
The long tab running along the bottom fits into a slot running around the glass cover.
The crossing lines in the rectangles , are slight bends that sheet metal workers put to flat panels to make them stiff. Again, the flanges running along one edge are inserted into a slot running around the outside edge of the glass cover.
Detail of the slot to accept the reflector flanges. Crude drawing.
A gimble rack for the bottom of the oven.