Just found four chinagraphs, one red, one yellow, and two black (one with clip), all the same design as the white one in MPN11's photo. All four were service issue from the 1970s, and marked 'Made in USA' on the top of the knurled knob (needed a magnifying glass to read it!). Also a ten pack of Black Wax Leads (seven remaining), marked with the Stationery Office Logo and Code No. 48-364.