That's an interesting thought, Donal. I wonder?
I'll take a look at them. There may be a Japanese/Chinese connection. The name comes up during a Chinese craze here in Australia (and New Zealand). The performer named as a "Sam Yeen performer" was an associate of the man I'm studying. They both played other Chinese instruments and did a Chinese act. They were billed as "The Minstrels of the Moon" at the time.
This instrument is also called a "Moon Guitar" and sometimes has little moons cut into the face. It looks more like a banjo with a wooden drum.
Cheers, Joy