Not worth much. They did use some surplus parts slapped into a worthless receiver of questionable material and poor quality. Do a Google search on National Ordinance 1903s and you'll get to read a lot of horror stories.
If you wanted to salvage some of the parts off of it, and you could inspect those parts in person before hand, and it was close to free, it might be worth it. I sure wouldn't part with $300 for one.
-Sam