On a related note, technically alot of the SKS' are American. Take a close look at the engraving on them at your LGS. Most SKS' I have seen are actually made in the states. VT or CT as I recall. I find it quite ironic.
Those are most definitely import marks. One has never been made in the US. They would easily cost more than an M1a due to the machining.
I've seen at least one SKS built here with parts from totally trashed SKS'. But that was a homebuild type deal using mostly imported parts.