Is it? Am i misreading this:
http://www.geocities.com/Athens/Acro...9/ltkxplan.gif
Or is it wrong? Did York Road/Way get moved at some point?
You are reading it wrong. The KX thameslink platforms are beyond where
the "york curve" meets the "widened lines", all the way on the south
eastern side of the victoria line, far away from the rest of the
complex.

The covered part of the KX Thameslink platforms are the covered bit on
the right, just before the tracks appear, on this aerial photo from
Google Maps:
http://maps.google.co.uk/maps?f=q&hl...&t=h&z=18&om=1

As you can clearly see, its quite a long way from the tube ticket hall
and even york way.

There is however, a slight inaccuracy in the map; you can go directly
from the western platform of the Piccadilly (the one nearest York way)
to the escalators down to the northern line. And it doesn't show any
of the non-public areas (like the old lift shaft areas) apart from the
york and hotel curves.

The york curve was used as a public walkway at one point decades ago,
I'm not sure why that changed.

Yes - but that puts the Victoria platforms to the east of the ticket hall,
and roughly at the junction.
Correct.

Fair enough. Are there any surface markers of the Victoria platforms?
No. They were built in the 1950s, long after lift access had been
replaced by escalator access. The victoria line's escalators cut
through the old lift shafts for the piccadilly (which is the tiled
circular building immediately west of WH smith), and the remaining
parts of the shafts are used for ventilating the victoria line
platforms (it feeds that wierd parallel not-publicly-accessible tunnel
slightly above and to the north of the western half of the westbound
victoria line platform).