What happened is that someone in the polish army got a chinese u-folder somehow.
When they cut the weapons up, they did not pull the chinese gun out from the polish ones. Centerfire did not know to check because they all came from poland.
You can tell that it is a chinese barrel because it will be smaller diameter then the polish.
If the front trunion is not damaged then you really made out on the chinese gun.
Now, for the pictures that I have seen in this thread, the barrel's where not rusty.
What was rusty was the slant brake.
The demilled trunions is what makes these kits useless IMHO.
I can deal with some rust. I can deal with missing 1 rivet out of the rear trunion.
But I can't deal with the front trunion being cut.
I am really glad I did not buy any of these kits.
To whomever purchased the kit with the laminated grip, I would check the dates on the trunion. Good chance you got a russian kit instead of polish