China Classic Stamps Forgeries: Help Needed

I am collecting China classical period, but I have no knowledge of how to discern forgeries. I search internet to find some article that could help me, but I did not find anything useful. Could anyone of you suggest a helpful internet link? I would be most grateful! I add a picture of my collection so far. Maybe there is expertknowledge among you to discern forgeries among my stamps. If useful I could send more detailed pictures! Greetings, Cor.

At a first glance; the first 3 large dragons are forgeries...

Consider joining https://www.chinastampsociety.org/

I'm not an expert ,but the I agree with perf 12,tath the first Candarin stamps don't look to be genuine .
You could see at http://stampforgeries.com/forged-st...of-shanghai/
There are not, from the same issue ,but there are plenty of images of forgeries of Chinese stamps.