I think I found the Australian who was one of the Four Rianos:
The Billboard, November 13, 1915, page 17
"Jack and Louise Kell have just closed their season of fairs ... Jack Kell is a member of the original Four Rianos, and still puts on his monkey impersonation." [no location given]
http://www.rootschat.com/links/01n9n/--
Indiana Marriages
St Joseph Indiana, 22 January 1909
John W Kell, born 29 March 1878, in England, son of William F Kell and Sarah Watson. occupation: actor, residence: South Bend, Indiana. parents' residence: Sidney, Australia
Louise Augusta Whilmine Buetow, born August 26, 1882, Milwaukee, Wisconsin, residence: South Bend, Indiana. occupation: manicuring. father: Albert Buetow, born in Berlin, Germany, living in Milwaukee. mother: Marie Kollar, born in Berlin, living in Milwaukee.
https://www.familysearch.org/ark:/61903/1:1:KZC5-8LJThey are also in Cook County (Illinois) Marriages, with a marriage date of 14 November 1912.
no image at familysearch.
https://www.familysearch.org/ark:/61903/1:1:N7CP-W52---------
SS Ventura, May 13, 1902, arriving San Francisco, from Sidney, Australia
William H Riano, 27, professional, born in US, last residence: US
five lines down:
John W Kell, 23, professional born in England, last residence: England, headed to San Francisco
https://www.familysearch.org/ark:/61903/1:1:QKMQ-SP49edited to add attachment