I've been working the Armour famlies around Westmorland for over ten years.MOST of the Armours are from Salisbury Pennsylvania.I have all of the earlier information about the the two sons of Robert and all their children.Your research should be easy.You need to check the the 1870 Census for John James Armour father's name.I can give you the rest of the information.By the way there is a Kendall in Beaver County PA not far from Westmoreland County.A different group of Armours settled there.I also have that research done ...so don't worry.
Here are the Armour/Armor 1870 index for Westmoreland
John C. Armor age 53 Fairfield Twp roll 1465 page 203
John G. Armor age 62 Ligonier Twp Roll 1465 page 355
William Armor age 58 Unity Twp Roll 1466 page 699
John Armour age 32 Ligonier Twp Roll 1465 page 378