There is hereby authorized to be appropriated from time to time, out of any moneys in the Treasury not otherwise appropriated, such sums as may be necessary to carry out the provisions of each convention and of this chapter, including—

(a) contributions to each commission for the United States share of any joint expenses of the commission and the expenses of the United States Commissioners and their staff, including personal services in the District of Columbia and elsewhere;

(b) travel expenses without regard to the Standardized Government Travel Regulations, as amended, subchapter I of chapter 57 of title 5, or section 5731(a) of title 5;

(c) printing and binding without regard to section 501 of title 44 or section 6101 of title 41;

(d) stenographic and other services by contract, if deemed necessary, without regard to section 6101 of title 41; and

(e) purchase, hire, operation, maintenance, and repair of aircraft, motor vehicles (including passenger-carrying vehicles), boats and research vessels.