Part of the answer, Benjamin remarried in 1927....(the easy bit)
Benjamin ILLETT m Harriett WILLIS July 24 1901 at Salvation Army Office Adelaide
He was 24 b1877, single, father Benjamin ILLETT
Book/Page: 208/247 ADE
Benjamin ILETT m Rhoda BERTRAM November 04 1927 at Res of Rev W A OBrien North Unley
He was 50 b 1877, widowed, father Benjamin ILETT
Book/Page: 313/416 ADE