It shall be the duty of such officers or employees of the Bureau of Land Management as may be designated by the Secretary of the Interior, in pursuance of instructions from the Secretary of the Interior or such officer as he may designate, to certify and affix the seal of the office to all patents for public lands, and to attend to the correct engrossing, recording, and transmission of such patents. They shall prepare alphabetical indexes of the names of patentees, and of persons entitled to patents; and shall prepare such copies and exemplifications of matters on file or recorded in the Bureau of Land Management as the Secretary or such officer may from time to time direct.