1931 Cal. Stat. 2317, An Act to Control and Regulate the Possesion, Sale and Use of Pistols, Revolvers and Other Firearms Capable of Being Concealed Upon the Person, ch. 1098, §9.

Every person in the business of selling, leasing, or otherwise transferring a pistol, revolver or other firearm, of a size capable of being concealed upon the person, whether such seller, lessor or transferor is a retail dealer, pawnbroker, or otherwise, except as hereinafter provided, shall keep a register in which shall be entered the time of sale, the date of sale, the name of the salesman making the sale, the place where sold, the make, model, manufacturer’s number, caliber, or other marks of identification on such pistol, revolver or other firearm. Such register shall be prepared by and obtained from the state printer and shall be furnished by the state printer to such dealers on application at a cost of three dollars per one hundred leaves in triplicate . . . [t]he purchaser of any firearm capable of being concealed upon the person shall sign, and the dealer shall require him to sign his name and affix his address to said register in triplicate, and the salesman shall affix his signature in triplicate as a witness to the signature of the purchaser. . . [t]his section shall not apply to wholesale dealers in their business intercourse with retail dealers.