Hi , reading your post re Alexander McLaurin and Grizel Campbell , i can recommend a book for you , Creag An Tuirc , by Neil McLaurin. it gives extensive history regarding many McLaren family lines.
Alexander and Grizel are in the book , with family listed , pages 285 and 286. mainly regarding the farms of Broich and Duchlage , from around 1670 on , with your Alexander's grandfather.
hope off help. Gordon