If you have been notified (officially, by the Court) of the bankruptcy, you cannot file a lien on anything. If you do, you will be fined by the Court. Keep the truck until someone comes looking for it, but be quiet about it. Chances are there is a creditors' lien on all of GFC's assets, in which case the truck doesn't belong to them anyway.
This is CABL.com posting #149638. Tiny Link: cabl.co/mM5G