As a dit name, Michaud & Sirois could be used together or interchangeably.Apparently Samuel chose to use Sirois even though he was baptized Michaud.It made it very confusing to find him though!I'm not positive this is your family, but there are some good signs.
We have his (supposed) baptism:
Pierre Samuel Lauronse Michaud, b. 19 May, bap 20 May 1864 Cacouna (St-Georges).
One nice thing is that the birth month and year closely match that shown in the 1900 Census.He was also a blacksmith like his (supposed) father, Pierre:
1900 United States Federal Census about S*IL Siroys Name: S*IL Siroys [Samuel Sirois] [Saul Siroys] Age: 35 Birth Date: May 1865 Birthplace: Canada Fr [Canada] Home in 1900: Cedar Creek, Lake, Indiana [Lake] Race: White Gender: Male Immigration Year: 1888  Relation to Head of House: Head Marital Status: Married Spouse's Name: Hattie Siroys Marriage Year: 1894 Years Married: 6 Father's Birthplace: Canada Fr Mother's Birthplace: Canada Fr Household Members: Name Age Sam'l Siroys 35 b. May 1865 Can-Fr, parents b. Can-Fr; blacksmith Hattie Siroys 25 -wife- b. Mar 1875 KS, fath b. Can-Fr, mh b. Ire Earl Siroys 4 -son- b. Jun 1895 IN Mable Siroys 1 -dau- b. Dec 1898 IN
It needs more research, but I think you should strongly consider this family (Pierre Sirois dit Michaud & Felicite Levasseur) as belonging to Samuel.Annie