Flying10UK,
Cinders is correct in that, feeding the fire of fake weapons is not what we are about, however, experience is the key to handling any Military produced weapon, regardless of country of origin.
It is only by handling these weapons, like the 4T that you get to identify, the correct serifs and numbering in areas not commonly known to the casual copier or faker.
There is an abundance of information on this site already as you know which if read carefully will give you what you seek, as it is carefully laid out to assist buyers so that they do not get caught, but more importantly gives you the confidence that you have the real deal in your hands and can quickly identify anything that doesn't look or feel right to you, after that knowledge has been gained!!
Good Luck.