On 18/02/2014 16:53, Roland Perry wrote:

[...]
A handful of Gateway stations would retain a travel advice office.

Which would have been able to sell tickets, which makes it a ticket
office even if it has a fancy name.

Do they sell travel tickets?

http://www.nationalrail.co.uk/SME/html/NRE_EUS/objectvalues/1809-0018963.html

The current TfL Travel Information Centres (of which that is one)
issue and top-up Oyster, and also sell paper Day Travelcards. UIVMM
they don't sell single journey tickets (i.e. a single Tube journey).

Would they be able to "load" a 16-25 Railcard onto an Oyster?

Yes - see:
http://www.tfl.gov.uk/tickets/18343.aspx#tkt-tab-panel-3


That's the reason I went to that particular office in the first place;
but the size of the queue, and the fact that they seemed to be serving
about one person every five minutes, made us decide to walk to Euston
Square station instead. Where there was no queue at all.