While I cannot add specifics to the Scottish scene, one point that might prove helpful when doing searches (or possibly even become a topic of lecture) is the difference between a "Cobbler" and a "Cordwainer". Some of my ancestors were Welsh Cordwainers, so I was interested to discover the differences (I presume there would be some degree of crossover into the Scottish!). In essence, the Cobbler worked with old leather, so repaired shoes etc.; while the Cordwainer worked with new leather only, so was a manufacturer of shoes and fine leather goods. Note that a Saddler or Harness-Maker of course would be different again.
The name Cordwainer originated from the type of leather often used by them - "Cordwain" or "Cordovan" leather - from Córdoba, Spain. References to the occupation date back to the 1100's.
Again, I do not know if the terminology is the same in Scotland, but even if it is not, there may well be Gaelic equivalents of the different words.
Hope this helps a little, and good luck!
