Some random thoughts:
I might be misunderstanding, but aren't we talking about two separate sections of the archive?
One is the currently archived/available/housed historical information (articles, photos); and the second would be a soon-to-be-created 'resource centre' for new contributions/donations and on-going research.
Do both sections need to be structured/organized along the same lines?
The first section is massive and 'authoritative' (if for no other reason than it's 'historcial'); but that the second section could be whatever (and whatever size) the USGA wants, i.e. it could be authoritative or speculative; it could be a simple catch-all resource for whomever was interested in searching or contribution (with a 'buyer beware' disclaimer), or a USGA- run 'experts forum' where contributions are 'open' for discussion/corrections/minority opinions until they get locked (by the USGA librarian) and added to the first section, i.e. the archive.
Also, a question -- are 'finances' at all an issue here? Does the USGA want or need at least some sections of the archive to be a revenue stream? (I'm thinking of the NY Times' archive of articles dating back to the 1840s; I think $14.95 allows you to search for, find, and download 100 articles a month.) I'm not saying I'd like to pay fees for research (I'm sure no one would), but just wondering if thought has been given to the possible need to make the archive in part self-financing, especially if it needs to be done absolutely right, and be self-sustaining.
Also, on the copyright issue (which I'm guessing will became an increasingly important issue in direct proportion to the success and growth and use of the archive): wow, it seems to me a really complex issue, and one that might require -- in some instances at least -- the USGA to be prepared to become an 'agent' for copywritten materials. But I'm way out of my league here....just some guesswork
Peter