The lead is a little bit short. Some of the history would be worth putting there, just a prose representation of what's in the infobox with basic opening (and closing) dates. Maybe a brief mention of the Crossrail connection.
I wonder if it's worth mentioning Euston Square in the lead? Might be unnecessary but every tube map has "Euston Square for Euston" on it. Maybe something like "the station is near Euston Square station allowing connections to the Metropolitan, Hammersmith and City and Circle Lines" would do?
This might be controversial (and I'm happy with "no" as an answer) but shouldn't it be The Strand?
The Underground station concerned has had several names, presently it's Charing Cross, but it was named "Charing Cross (Strand)" between 1914 and 1915, and "Strand" between 1915 and 1973, but never "The Strand". --Redrose64 (talk) 19:50, 14 July 2015 (UTC)[reply]
Also, the street name is just "Strand" on maps and road signs. I agree that "The Strand" is commonly used, but I suspect that this is because a single syllable word feels odd when used in this way.--DavidCane (talk) 00:36, 16 July 2015 (UTC)[reply]
"led by American financier Charles Yerkes which raised the money for construction" - as we know what the money's from already, maybe "the necessary money" might be better?
The WCML stopping service doesn't stop at many stations south of Watford Junction - between Euston and Watford Junction, they can call only at four: Queen's Park, Wembley Central, Harrow & Wealdstone and Bushey. The LO route between Euston and Watford Junction, calling at 17 intermediate stations between Euston & Watford Junction, is not the WCML but the Watford DC Line. This uses two platforms (9 &10) at Euston, and two of the six tracks between Euston and Camden Junction which are shared with the WCML and dual-electrified. Between Camden Junction and Watford Junction the DC line runs roughly parallel with the WCML, initially on the north, but it dips under the WCML at Intersection Tunnel to run along the southern/western side, although there are stretches where it is some distance away, particularly in the Stonebridge Park/Willesden area and between Bushey and Watford Junction where at Watford High Street Junction the separation becomes as great as 800 metres (1/2 mile). It is the Watford DC Line which shares tracks with the Bakerloo line between Queen's Park and Harrow & Wealdstone. --Redrose64 (talk) 16:27, 15 July 2015 (UTC)[reply]
"the former C&SLR route to King's Cross and Bank", as this is the first mention, a link to Bank and Monument stations would be useful Done
"to a new platform some way to the south of the original alignment" - not sure "some way" is necessary; it tends to invite the question "how much is 'some way'?"
"from an intermediate circulation level" - not sure what this term means, I assume its to accommodate the flow of foot traffic, but casual readers may be confused by it
I've added an extra word to clarify. It can certainly be confusing to passengers. Those changing from the Charing Cross branch Northern line platforms to the Victoria line have to pass two sets of escalators up to the ticket hall and a set down to the Northern line Bank branch platforms before they get to the Victoria line escalators. Long ago I created a plan of the station based on a London Underground diagram from the 1960s, which showed how the station was reconfigured. It was removed from Commons as it was considered a copyright infringement. Given that it would have been Crown copyright, it is probably free to use now. A copy which must have been taken from wikipedia before deletion is on the subterranea britannica site here. I still have the larger original.--DavidCane (talk) 00:36, 16 July 2015 (UTC)[reply]
Yes, Crown Copyright expires on 1 January following 50 years after publication, so a 1964 map would have been deleted on Commons in 2008 but is fine now. I wonder if we can get it restored? Ritchie333(talk)(cont)09:42, 16 July 2015 (UTC)[reply]
I think that would be useful - I've had a look through a news and book search, and TfL archives, but there doesn't seem to be anything that talks about the specifics of the pre-Victoria line layout. This book looks like it should have the information but there's no online preview so I can't easily check. Ritchie333(talk)(cont)09:42, 16 July 2015 (UTC)[reply]
I've found a report from the London Underground Rail Society. Though it's not affiliated with TfL, I'm happy to believe that whoever wrote the report is a subject expert and what is contained in it is factually correct. In any instance, the facts in question are backed up by the photographs you linked to. Ritchie333(talk)(cont)09:52, 16 July 2015 (UTC)[reply]
This section is unsourced and very brief. I think we can drop Euston bus station down to a "See also". I have put in bus routes for completeness on street articles, but I don't think it's necessary here as the buses don't directly go to the tube station. Done
I normally put a list of bus connections in for tube stations, but with the bus station article already providing a list of these, I thought it easier to link to that rather than duplicate the list. I see Vincent has put in a full list so I'll leave that as is with a couple of minor copy edits. I have linked the bus station from the text of this section.--DavidCane (talk) 00:36, 16 July 2015 (UTC)[reply]