The MUIRHEADs and George ADAM (and his family), lived only a matter of about 5 miles apart at Templeton and Prebbleton.
All the electoral roll listings for George ADAM show his occupation as "Labourer".
Having scoured NZ records (particularly newspapers) I found nothing to connect the MUIRHEAD and ADAM families. Often times newspapers give up information which provide connections ... but perhaps it needs to be considered that there was a big age gap between the children of these two families (i.e. George ADAM's children didn't begin arriving until the early 1860's ).

~ Lu