I doubt the PDF would be very interesting. There are enough clues in the human-readable parts: it's an invite to a benefit event in New York (filename calls it DBC12) that's scheduled on December 10, 2012, 8pm... Good old-fashioned searching could probably uncover what DBC12 was, although maybe not, it probably wasn't a public event.

The recipient is also named in there...

There's potentially a lot of files attached and printed out in this fashion.

The search on the DOJ website (which we shouldn't trust), given the query: "Content-Type: application/pdf; name=", yields maybe a half dozen or so similarly printed BASE64 attachments.

There's probably lots of images as well attached in the same way (probably mostly junk). I deleted all my archived copies recently once I learned about how not-quite-redacted they were. I will leave that exercise to someone else.