Barry Salter wrote:

In terms of the routeing guide, it'd need to be Willesden Junction for
the reason given above. In terms of physical layout, probably Harlesden
or, more likely, Wembley Central, given the line from Willesden West
London Junction to West London Junction doesn't go anywhere *near*
Willesden Junction Station and, of course, the AC lines don't have
platforms between Wembley and Willesden WLJ.

I asked this question in the NG the other week, and the consensus was
that Willesden would do, or if not Stonebridge Park, given that
typically the existence of platforms doesn't matter. I think I'd go
for Wembley Central, though, on the grounds that it would definitely
avoid arguments and wouldn't likely cost a lot more.

The big question (and I think it's quite an important one) is whether
the DC lines are part of the WCML, or whether they form a set of
distinct loops joined only to the WCML at Watford, Bushey, Harrow,
Wembley Central and possibly Queen's Park. The same question could be
asked elsewhere - are the slow lines through Euxton Balshaw Lane, or
Thirsk, or Levenshulme/Heaton Chapel and so on distinct loops because
not all trains pass a platform, or are they part of the line?

That said, the question will be moot once LUL take over.

Neil