Singular entity, plural name/nickname -- verb form?

In writing about the National Archives, I got to wondering about subject-verb agreement. The National Archives and Records Administration (NARA, often called simply The National Archives) is one entity, but when using the nickname, it would appear at first glance to be plural.

So, even though Archives is plural, because it is a single entity, does it still take a singular verb?

Note: I see on the NARA website, in the menu at the bottom, there is a link labelled What is the National Archives? so it would appear that they believe the nickname is singular.

Does it matter that the full name of the agency is the National Archives and Records Administration? When using the full name, I think it is clear that the verb should be singular (to match with the singular administration):

The National Archives and Records Administration is the nation's record keeper.

I'm just not 100% certain about the situation when using the shortened nickname:

The National Archives is the nation's record keeper.

I found a question singular entity as a collection of subjects that is similar, but there does not seem to have a definitive answer and does not have the same twist of the full name being obviously singular.