Thanks Mr. MacDonald,

It was that "pivot [on] a large plain ground..." which caused me to reconsider Pattern No.148.

In your second image, the "white" guard stripes to the dark sprainge which flank every pivot, seems difficult to mesh with Perth/Drummond of Perth or Spens.
But, as you stated, B&W imagery or, even Sepia Tone, depended highly on chemical bath for exposure. I have a chart which allowed for interpretation of the colours
in these types of images. When I return from work I will post it for anyone.

Thanks again,
Ryan