...I don't know what you're talking about Vlad. Were there two African American actors on DS? And an Asian actor?
Midnite just posted the information on the actress appearing as a Colllinsport nurse (whose credits I didn't have).
Istvan was played by Henry Miller, a black actor who specialized in playing "heavies." Although he appeared in about four episodes in the 1897 sequence, he never received credit, apparently because his character didn't speak. Sad, because this was an "extended" appearance or principal role.
Mr. Nakamura, an art dealer associated with Olivia Corey, was played by Japanese born actor Sho Onodera.
Incidentally, I discovered the inspiration for this character a few years ago, but I've lost the specific information. A little-known series of occult-supernatural novels featured a Japanese art dealer/detective named Mr. Nakamura.