Wow. Nice stuff!
James Brown (1853-1897) was not Scottish himself (he was born in Alnwick, Northumberland) but both his parents were. His father was famed for his Scottish skits performed at Alnwick Castle so presumably that is James' basis for that character.His elder brother John Robert Brown (1851-c1929) was another artist who drew for the 'Graphic' and later 'Black and White'. After James died, his brother took over drawing duties on McNab.The two brothers also ran a successful business as designers for events and decorating public buildings.
Thanks for the biographical details - much obliged!