Miller's house, 13, John Street

I came upon this interesting doorway this morning and have now discovered that this is said to be the oldest datable dwelling in Stromness. 

The carved sandstone above the door bears the coat of arms of the Millar and Nesbet families and is dated 1716.
So it seems it was not, as I imagined, the home of a miller who made his living grinding corn. 
In the early nineteenth century it was occupied by a Lt James Millar, who had a distinguished naval career.