Have spent some time tonight following his McKillop line - the 'Billy Mac' in entertainment troupe in WW1 was William Alexander McKillop b.1889 Derby, son of an Alexander William Iffil McKillop (contractor) born in Tobago, West Indies in 1868, son of John McKillop (Shipsmith) born 1835 Liverpool, son of John McKillop (Shipsmith) born ca.1793 Scotland (an online tree states Oban, Argyll).
So ultimately back to Scotland, Rosinish!
Annette