Hi again, I'm writing not to repeat the question, but to add that I found the owners of 4 Joanna Terrace in the 1925 Valuation Rolls, as well as names of their tenants.  It looks like this pair, John and Margaret Taylor, living at 268 Bath Street, Glasgow, also owned 2 Joanna Terrace and there's a tenant there, James Young, sub-postmaster, that I'd like to know more about as well. He may be a relative of Rachel Paterson Young, who lived at 4 Joanna Terrace for at least a year, up until July 1, 1927.  I've searched a few directories but could not find records for James Young as a member of the postal service.  Thanks, and sorry to add to your labors.