I'd have thought the most common version would have been Frappier/Frappierre...His grave in Nebraska says
Birth 1 Nov 1836....
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=75858091The U.S. census seems to have George Ellsworth's ( Born Illinois) info quite often as Frappie or Frappier? The graves and later descendants b. Nebraskaseem to be using the Frappia spelling...although do see the rest of them in 1880-1910 as Frappia...I imagine this would have been the phonetics of the census takers..
You'll be looking for Olivier (Pierre) Frappier... as per the 1852 census...I imagine you have confirmed something to prove this is the correct one?
http://www.automatedgenealogy.com/census52/View.jsp?id=33975&highlight=38 The Drouin files with a November 1st or close date will help confirm. Looks to be good, as the one of same age Ontario appears to be accounted for... .
Mother, Félecite may be found as Henault( Although marriages of Olivier's siblings, Joseph & Aléxis say Enos as well so depends on who is filling in the information)...Let us know if you need help along the way...
But a small hint if you want to start searching alone, is that it looks to be the in-laws are next door on the 1852 census