I had the same problem Odd Shot with the mag release. Mine was due to the rivets put in. They were exactly flush, but angled slightly, so it prevented the mag release from depressing completely to release the mag. After putting the mag in and out the two parts have worn into each other and function fine. If I were you, file the mag rivet if that is the problem first instead of the mag release.
Are you happy with you barrel indexing? After looking at mine from all angles, I think I can conclude that it is fine.
The fit and finish on my Polytech (Lever Arms) is great. The guy said they were brought in last year.
Could you post comparison pictures of your Poly vs Norinco for reference for potential new buyers?
Thanks for the advice.
I've already changed out the parts I wasn't happy with on the Norinco and re-indexed the barrel.
Pic's of the before are here:http://www.canadiangunnutz.com/foru...Norinco-M305&p=7969348&viewfull=1#post7969348

The barrel was so out of index that the op-rod was hitting it and binding up. See the worn part on the barrel in the middle of the picture.
The rifle is all sorted out now, and life is good.
There's no point posting any pic's of my Polytech as any pic's I take of it would be virtually identical to your's.