"SECTION 161. Records to be Kept by Wholesale Dealers. - Wholesale dealers shall keep records of their purchases and sales or deliveries of articles subject to excise tax, in such form as shall be prescribed in the rules and regulations by the Secretary of Finance. These records and the entire stock of goods subject to tax shall be subject at all times to inspection of internal revenue officers.

"SECTION 162. Records to be Kept by Dealers in Leaf Tobacco. - Dealers in leaf tobacco shall keep records of the products sold or delivered by them to other persons in such manner as may be prescribed in the rules and regulations by the Secretary of Finance, such records to be at all times subject to inspection of internal revenue officers.

"SECTION 163. Preservation of Invoices and Stamps. - All dealers whosoever shall preserve, for the period prescribed in Section 235, all official invoices received by them from other dealers or from manufacturers, together with the fractional parts of stamps affixed thereto, if any, and upon demand, shall deliver or transmit the same to any internal revenue officer.