1. These magazines may be built in accordance with one of the following 2 options:
(a) 1st option: A metal box or case with each side solidly constructed and with cover or pivoting front panel, all fabricated of welded steel plates 1/4 in thick. Such cover or panel shall have an insulated lining and shall overlap the edge of the box by at least 1 in along its whole perimeter. Such cover or panel shall have hinges and a closing system identical to those described in section 6 of Schedule 2. The inside shall be lined with a nonsparking material.
(b) 2nd option: A box or case with each side solidly constructed and with a cover or pivoting front panel made of 2 layers of plywood 3/4 in thick sandwiching 5/16 in, 18 gauge, expanded steel mesh extending around the corners, all to be covered on the outside with a tight cladding of galvanized iron of a thickness not less than 20 gauge and overlapping at least 4 in at the corners and 2 in at the joints. The first inner layer of plywood may be replaced by tongued and grooved boards 2 in thick. The cover shall be made in an identical manner to the sides and shall have strong hinges fastened inside and riveted. The box or case shall be equipped with 2 maximum security, independent, anti-theft, mortise locks with individual keys which cannot be duplicated except by the manufacturer, only after identification and signature, or alternatively, with any other locking system guaranteed to give equal security.