There was an Italian guy boxed out of the New England area. Willie Pep. No punching power but was a master in every phase of defense.
Tommy Loughran is another very good one. Only stopped 3 times in over 150 fights, despite a not invulnerable chin.
We have of course no footage of Jack Britton - but with a streak of 342 consecutive fights without a ko defeat, he must have been pretty sound defensibly, I would guess!
From what I've seen, I'd agree Pep and Canto are the top two. From Young Griffo, hell from Malenkomas, to Floyd Mayweather Jr., there's been a ton of great defensive fighters.