Correction YA Purcell's father was Macomb not Malcom(b). I got caught by a census taker's misspell. Macomb is in Boone county in the 1830 census and in 1850 census is an owner of one slave. Boone County History lists he (Macon sic) and his wife as charter members of Gilead Primitive Baptist Church in 1832. This now non-extant church does have a cemetery but it is in poor shape and only partially read. No Purcell's listed but church was active to turn of the century and does have burials of the right time frame.
Martha Purcell, YA's sister married Silas Ruby Davenport whom we have discussed before I believe. YA's 2nd sister Cynthia lived with the Davenports. They are all buried in Randolph County.
The Vernon county connection I don't think will hold water as there are a number of Purcell's with conflated and confused records trying to make YA and JA the same guy but clearly they are not! So ignore the Montavello claim for now. It's likely a red herring