Question about rusted dug-up relics
Does anyone know what the ATF laws are regarding rusted dug-up relics that are non-operable and can't be made operable? I know of a case where a friend of a friend of a house-sitter for the butler of a masseuse may possibly have come across a WW2 heavy MG relic that had been in the ground for 30+ years and is in the condition described above.
When new and functional it would clearly have required being torched and demilled. But in this case, it can't be made functional and the receiver, barrel, etc. is rusted. Is it necessary to have it demilled since it can not be made functional? What is the ATF policy on this and are there any CA laws requiring special treatment of something like this? Does ownership require special paperwork and if so where does one go to submit this paperwork?
Thanks in advance.