Unfortunately two of the first occupants of the square are currently proving very tricky to get much beyond the basic facts. John Gordon and Nicholas Megraw, where are your histories? :-(
I have a few Megraw details (though most not verified yet) as he had a tailor's business on Bold St (Megraw and Heron), but Mr Gordon is proving quite elusive. He must have been a 'name' to get one of the first houses but his claims to fame are eluding me so far. If anyone knows him, do give me a shout!