There are tiny tacks in the surface of the ruler, which insert into holes on the opposite side for stability when closed. See close up photo. It looks like a bit older version of the 268 than others I have seen, with no patent mark, no manufacturer mark, and no Made in USA.
Antiques, Art, Vintage
VINTAGE 24 FOLDING WOODEN & BRASS MEASURING RULER No 7012 £5.99 - PicClick UK
Vintage hard to find 24 inch folding wood and brass ruler. Boxwood brass no. 268 made by the Master Rule Manufacturing Co. In New York USA. In good
Rare Master Rule Manufacturing Co. 24 Boxwood Brass No. 268 Folding Ruler
Vintage UPSON Nut Co No 62 Boxwood Wood Brass Folding Carpenters
VINTAGE MASTER RULE No. 268 24 Folding Boxwood & Brass Ruler New
There are tiny tacks in the surface of the ruler, which insert into holes on the opposite side for stability when closed. See close up photo. It looks
Vintage No 268 Folding Ruler 24 Wooden Boxwood Brass Tips
MASTER RULE #268 Vintage Folding Pocket Ruler 24 Four Fold
wood folding ruler 24 - warranted boxwood - tools - by owner
ANTIQUE FOLDING RULER Wood Brass 24in £6.74 - PicClick UK
Stanley Boxwood and Brass 24 Inch Folding Ruler – critical EYE Finds
メジャーテープ、ルーラーの定規 ビンテージ, 公認海外通販サイト
3 X Vintage Wooden folding Rulers Rabone Boxwood 2 X 24 1 X 36 yard rule £9.99 - PicClick UK
VINTAGE MASTER RULE No. 268 24 Folding Boxwood & Brass Ruler New