I have found pretty much an exact match of this one beautiful little bone and brass folding ruler, dating it to about 1820, British. All of the etched numbers remain completely readable, as do the markers, in 1/8" inch increments, and the brass pin to hold it closed is still in place. Just a beautiful little object whether to be used or not, and a pretty special gift I'd say.
6 inches long when unfolded. Folded: 3 1/8" x 7/16" x 1/8". Beautiful condition.