According to Find-A-Grave for Holy Cross Cemetery located in Butte Montana, the Cyril Joseph Vuilsteke who died 28 Jan 1937 was born 26 Nov 1881. All newspaper articles I posted in February relate to this gentleman.
In the 1930 census he was residing in Meaderville, Silver Bow, Montana as a boarder who was a divorced man.
In the 1920 Butte, Silver Bow, Montana census, he is listed as Cyryl Volstack, residing at 635 S Idaho (same address as his WWI Draft Registration form) with his wife Florence (born Colorado), daughter Fearl (born ca 1915 Montana), and son Lewis (born ca 1916 Montana, real name Harry). His year of immigration is listed as 1899.
Fearl married Thomas C Gilkey in Butte 27 Sep 1937. Mother listed as Frances Stewart nee Pierce. - According to the 1930 census, Florence was married to Russel Stuard/Stuart.
Harry married Iva Allen in Butte 9 Nov 1940. Mother listed as Frances Smith nee Pierce. - In the 1940 census Forence was married to Harry Smith.
Harry C Vuilsteke, according to SSDI, was born 30 Sep 1916, his SSN was issued in Montana, and he died Jul 1984 with his last residence reported as 98366 Port Orchard, Kitsap, Washington, USA. The Washington Death Index has his death date listed as 23 Jul 1984 at Port Orchard.
I hope some of this information will help you "key in" as from which family Cyril descended.