Ms and As—match those in an 1885 van Gogh painting. “As soon as we saw the Ancher, I knew we were right,” art historian and LMI Group researcher William Havlicek tells the Wall Street Journal.

Tiger, oil on canvas, 1912. The artist’s vibrant animal paintings were based on careful study, including hours spent observing big cats at the Berlin Zoo. Lenbachhaus Munich, Donation of the ...