You can get a new serial from the ATF. There’s a form for it. I’ve seen a Kragicon with a stamped in number that started with ATF.
There’s always the chance that they’ll decide it’s easier to destroy it though.
For me personally, it wouldn’t be worth it. I may purchase a firearm in a case like this if I had the opportunity, but I’d just part it out and destroy the receiver....which is probably also illegal so don’t listen to me haha.