Looking for info for John McKay married to Elizabeth Guinn, (b. 1837, d. 1924), children were George Henderson (my g-grandfather), Mae, John, Esther, Whittington, David.

George married Sarah Cudney (daughter of Richard Cudney & Martha Miles). My grandfather, Orval, did genealogy research in the 40's, traced family back to Scotland and changed spelling of family name to Mac. However, his records are missing, no one knows what he found. Anybody out there recognize these names? Thanks for any info.