Sorry, Brakes, I can see where you’re going but that’s not right. Or rather, it is, except the Mandelin was superseded by Wesson’s Annexe in the 1932 refresh.
The whole of rule 23 (which, as I’m sure you know, has always been controversial) was overturned as its frankly lunatic restrictions on diagonal inter-zone travel at weekends meant the it was practically impossible to ever get anywhere without going through Bank, even carrying purple tokens. And I’m sure I don’t need to explain the implications of that.
I can only assume you’ve got an old copy of the Almanac. Fortunately, I’ve got a current tournament edition right here. The full Annexe is obviously too long for me to transcribe here (plus, y’know, Copyright), but the gist of it is that Wesson rather elegantly resolved the Bank problem and subsequent Jameson’s Conduit shunt (which, let’s face it, was messy at best) by supplementing the Northern Line with an extraordinary bus service which, critically, can be assumed to be in place as required to bypass Bank completely. Thus, long plays can be made without having to specify “change at Euston, collect a blue token, get the bus, blah blah” every time. The result being a much faster, more flowing game.
So, Edd’s move was correct; he even mentioned that it was a ‘long play’ (though technically he didn’t need to) presumably to avoid this sort of confusion.