Hi,
I didn't find their deaths in the WV Early Vital Records,
www.wvculture.org/. Death records weren't required during that time period.
Nicholas County records are on microfilm at the Virginia State Library,
www.wvculture.org/history/archives/. they have wills 1820-1969. You might find them in those records.
You can contact the Nicholas County Historical & Genealogical Society,
www.facebook.com/ and ask if they have indexed death notices or cemetery inventories.
Also there is a web site for Nicholas County Historical Society Cemetery Project,
http://nicholaswv.org/ that might have info about where they were buried. Successful Searching!