The Chinese did not form the NORINCO company until 1981. The Viet Cong converted U.S. 1911 pistols to fire the 7.63 X 25 Toc.
The Norinco 1911 was made from virgin steel. They were Banned from U.S. Import in 1993. They are prized for their lower receivers for building Compt. 1911 pistols. Keep your 1911 it is gaining in value every year. I wish I had bought a few. Good luck and prize your dads memories.