Model, of Oblique Dovetail Halving carpentry joint, joining two beech-wood blocks: stamped with ‘43’ on block with Dovetail ‘Socket’; and stamped, plus written in ink with ‘43’ on block with Dovetail ‘Tail’, by Polytechnisches Arbeits-Institut J. Schröder Atkiens-Gesselleschaft, Darmstadt, Hesse, Germany, 1868