Missing factory code and type 56 stamp.
Machining on both sides look the same. I’m not detecting machining or scrubbing of serials. It appears to be the same rough machining for mid era Chinese production.
Let me know what other images would be helpful.
(https://i.ibb.co/RkT4jkpx/IMG-6568.jpg) (https://ibb.co/YFBT0F7z)
(https://i.ibb.co/yckbpCxY/IMG-6569.jpg) (https://ibb.co/0R9dKLzF)
(https://i.ibb.co/0ycmbdvm/IMG-6570.jpg) (https://ibb.co/zVrQv0DQ)
You're in Canada right Mike? If so, there's a good chance the S/N two digit prefix is the 20XX year of production/refurbishment/export. The Chinese did this in the US from 88 to 94 with many of the 'commercial' imports, but by 94 the AWB and other restrictions had gone into effect which eliminated imports. Canada enjoys Chinese milsurp firearm imports to this day, and the thus numbering scheme continues there.
Thanks RM this makes sense