The Shur-Rite line of pencils was a product of the Sandfelder Corporation, which had offices in Chicago, Illinois and Attleboro, Mass. I'm not sure whether the company was responsible for manufacturing the product; an advertisement from 1921 states that "We have been making jewelry for some time" but also says "retail dealers everywhere supplied by the jobbing trade." The patents for these pencils was issued to "Fabart Instrument Company," an Illinois Corporation.
(click on pictures to enlarge)
Shur-Rite pencils have wonderful detailed imprints. The nickel plat ringtop and one of the nickel-plate side clip models are imprinted "Pat. Applied For." The gold filled ringtop and the other nickel-plate side clip model are imprinted "Pat. June 14, 1921 Others Pend." The gold filled example has the 1921 patent date and "others pend.," but doesn't bear the Shur-Rite name.
The original patent was applied for by Julius Swanberg (see the Swanberg page for his later products) on November 10, 1919 and issued as number 1,381,517. View here. The "Others Pending" must refer to Swanberg's improved design, applied for June 2, 1921 and issued January 27, 1925 as number 1,524,062. View here. I know of no examples that have the later patent date on them.
Pull the top on one of these, as I did with the one at the bottom, and they easily dissassemble to reveal how simple they are. The lead drive simply holds to the walls of the barrel by friction and moves up and down with a screw.