As I recall (and my AI23b course at Cosford was in 1965, so it's going back a bit) 23b had a number of extra features, plus data link which was never inplemented at the ground end so not used in practice.
The modified wire wrap prevented a weak point at the first few corners where the post deformed the wire. The 6 (?) turns of uninsulated wire gave 24 airtight contact points in theory. There was a long and boring Ferranti document relating to acceptable techniques.
And yes, 1970's vintage PDP8 @ PDP11 backplanes were wirewrap.