No luck with Cathcart Street School - there must be photos of it out there somewhere - but I have managed to find some of Marion Street/Camden Street, admittedly only from the mid-70s, but they're better than nothing...
Description: Marion Street looking west
Description: 30-68 Marion Street & Star Yachts (Denye's)
Description: 21-43 Marion Street
Description: 62-68 Marion Street
Description: Camden Street from Conway Street
Description: Camden Street/Dacre Street junction
Description: Camden Street/Marion Street junction
Description: 32-36 Camden Street and the Angel
Description: Camden Street, Price Street end
Description: Rowland Street looking towards Marion Street