After some research in the Madison County geneology site, I discovered the following persons/facts:
Roswell Percival was a landowner in the Town of Lenox, Madison Co. during the years 1835, 1836 & 1837. (I've never heard of him before.Perhaps his presence there attracted Eugene & Grace back to the Town of Lenox about 1870.)
Polly Percival, 3rd husband of Mr. Kern(?) died 12/7/1894 at the age of 83 and is buried in the Skaden Family cemetery, Town of Stockbridge.
E. Homer & Grace, my ggrandparents, were listed in the Farm Journal 1917 rural directory as farmers owning 80 acres (my family's homestead for generations), two horses and 12 cows at RR#2 Canastota, Town of Lenox and having a Bell Telephone.
Blanch Percival, housekeeper, and Iva Percival, clerk, lived on East Center Street, Canastota, NY, according to the 1917 Village directory.(I've never heard of them before.)
As yet unidentified Percival(s) is/are listed on pages 470 & 510 of the Town of Lincoln Birth, Death & Marriage register for 1896 - 1946.