from the pics provided i would guess most of the lower parts and furniture have been replaced.
furniture has most likely been replaced. original would have been green.
the rubber coated sling swivel would indicate it's more than likely a later Type D
pistol grip is later
selector is not original. original would have been dimpled and not have the notch on the right side
pivot pin is not original
takedown pin looks darker than original and not dimpled
charging handle is the later one and not the triangular
flash hider is the later improved 3 prong and not the original "duckbill"
bolt catch is a later one
what does look original from the pics
many circles mag button
bolt carrier
ejection port cover
sight wheel
what looks more than likely original but need better pics to confirm
magazine
upper receiver
if the barrel is original w/ cast FSB, it shouldn't be too hard to do an original restoration. you have a lot of the hard to find parts like the lower receiver
.