:I'm not sure. These days their emphasis is on digitizing, but I suppose they haven't reached these yet - I presume you've checked?  If you just want sample items I'd expect some to be on their site already, which might count as 2-D, and so be uploadable to Commons.   was Wikipedian-in-Residence there for a year recently and would know better than I. Have you asked this lot if there are some open images?