A fabulous pair of polycrome Scrimshaw porpoise jaw bones circa 1840

One jaw bone depicts a tree above a full length portrait of a woman in Victorian dress reading a book. The other jaw bone depicts a tree above a full lenth portrait of a woman disrobing. Mounted on a contemporary wooden plaque. Height: 20 1.2" Width: 6'. Provenance: The Thomas Mittler Collection, The William Boylhart Collection. Illustrated in Nina Hellman's comprehensive 2015 volume entitled "Through the Eyes of a Collector: The Scrimshaw Collection of Thomas Mittler," figure 112.