This week's historical mysteries focus on a Spanish-language movie filmed in 1931 at the Maverick-Zachry House and Mills Dewey slot machine that may have gone to the San Antonio Conservation Society.

At the Pacific Pinball Museum in Alameda, the first blinking, brightly lit machine to catch my eye is “El Dorado,” a 1970s-era game, replete with bucking horses and cowboys, that once made an ...