"She arrived filthier than any car I've ever had."
I wish I could say the same. I once found a mouse nest in the bellhousing of a tbird donor car. I suspect the mouse was the fuzzyskeleton I found ground into the interior.
Looks like she did clean up well. Have you compression tested the engine yet for peace of mind?
One of my 5.0 donors had only 95K mi on it but compression was a bit down on the cylinders.
It still drove without any issues (it's now my backup race engine) but it's something worth verifying on a new purchase.