Very likely to be Berdan primed. Just sayin'
A Decade ago, surplus Port. 308 was very GTG... so it will be dependent on its storage for all these added years.
If memory serves me, it was sealed at the neck.. so it might shoot better, if the bullet seal was broke. ( seated slightly shorter )
FWIW... around 2015, you could buy 1K for around $150 plus shipping.