Unfortunately there really is no such thing as "expungement" anymore in the sense that the records no longer exist. They do and they always will. You just have to accept that as a practical reality.

Copies of documents themselves are not enough. You need two things. First, a letter in plain English from your lawyer "To Whom it May Concern" which explains without puffery what happened and the legal impact of what has happened. Conclusions are not good enough. No reason for a CBSA officer at some border crossing to understand citations to Pennsylvania law. Second, attested (certified) copies of the appropriate court orders and docket entries. On second thought, spend the money now and get yourself a bunch of those attested copies.

Keep one with you, keep one in a safety deposit box, and keep one somewhere else.

You can't do much more.