(3) Notwithstanding anything to the contrary in this Act — (a) where the value added by any process in the manufacture of sales duty goods or excisable good specified in Section B of Part 2 of Schedule No. 1 is, in the opinion of the Commissioner, low in relation to the manufacture selling price of such goods, or where any process in the manufacture of sales duty goods or excisable goods specified in Section B of Part 2 of the said Schedule presents in his opinion exceptional difficulties in the collection of sales duty or excise duty specified in Section B of Part 2 of the said Schedule in respect of such goods, the provisions of subsections (1) and (2) shall apply, and due entry of such goods shall be effected at such stage in the manufacture of the said goods as he may determine, and the processes which shall be deemed to be included for the purposes of calculating the value for sales duty purposes or for purposes of excise duty specified in Section B of Part 2 of the said Schedule of such goods shall be as determined by him; (b) the Commissioner may, subject to such conditions as he may impose — (i) where the production and disposal of any sales duty goods or excisable goods specified in Section B of Part 2 of Schedule No. 1 are performed by different persons, or under circumstances rendering it expedient in his opinion to do so, issue one licence under this Act in respect of the premises of two or more persons concerned, and thereupon each such person shall be jointly and severally liable for the sales duty or excise duty specified in Section B of Part 2 of the said Schedule on all the sales duty goods or excisable goods specified in Section B of Part 2 of the said Schedule anyone paying, the other or others to be absolved pro tanto; (ii) include in a special duty warehouse licence issued under this Act in respect of the premises of any manufacturer of sales duty goods or excisable goods specified in Section B of Part 2 of Schedule No. 1, any warehouse, depot, agency, branch or other storage place approved by the Commissioner and in which any such goods owned by such manufacturer are stored, and thereupon such goods shall, for the purposes of Act, be deemed to be in the licenced special duty warehouse of such manufacturer, and the licensee concerned shall be liable for compliance with the requirements of this Act including liability for the sales duty or excise duty specified in Section B of Part 2 of the said Schedule on such goods so stored; (iii) and in such circumstances as he may deem expedient, license the premises of any dealer in sales duty goods or excisable goods specified in Section B of Part 2 of Schedule No. 1 as a special duty warehouse under the provisions of this Act, and thereupon such dealer shall comply with