Do you still do look-ups for the Guild?
This is my Great Great Grandfather & his son-in-laws father. My speculation is that since they were in the same trade, it is how their children met. Both are listed as Shoemakers (journmen) on documents (census, vital)
James Johnston (1827-1897)
12 Tureen St. Glasgow
Thomas Young (1822-1892)
2 East Wood Lane, Gallowgate, Glasgow