In the message: ...
wrote:

How close is the CTRL tunnel's alignment to the North London Line
between Stratford and St. Pancras? It looks identical, anyone know?

I presume you mean 'it looks identical on the maps at www.ctrl.co.uk '.
And this is confirmed by the location of several works sites along it, eg at
Canonbury Junc. and beside the Graham Rd. curve. But there is also one a
couple of hundred metres northwest of Hackney Wick station, and so I think
that the CTRL tunnel alignment runs almost directly between a point beneath
Homerton station and the 'box' for Stratford International station. Details
of the position of the latter can be found eg on the sketch maps at the
www.tfl.co.uk site on the proposed DLR extension to it.

Regards,

- Alan (in Brussels)