Not sure if this applicable, the shield the lion is holding is possibly an heraldic way of distinguishing other branches of the family (cadet branches) from the senior line.
The smaller shield altough we are not certain what the details are appears to have a checkered band across the top, this is a Fess in heraldry. The most famous fess and one of the most widely spread is that of the Stewarts.
I admit this is only conjecture until the detail is clearer.
None of the clans or Industrial families or noble families of the Caithness and Sutherland areas have this as family crest,
Maybe a servant from a visiting family from the south perhaps for an estate shoot lost it.
James