Casting marks and numbers on the gas block rear sight block etc suggest a fair amount of parts have started life on real steel production lines and pulled before they were finished, or pressed on orignal tooling. Others are airsoft specific (eg the outer barrel) but using similar grades of material to the originals.
Makes sense for the chinese - they work thru all their weapons variants then they've got a full range of airsoft training weapons for their own armed forces with weird western folks to pick up the bill (and they probably make as much per unit as they used to do selling semi auto centrefire rifles to US importers but with none of the political hassles).
One thing I would say crunchmeister is that the T56 is basically a 400+ FPS rifle equipped with a 300 FPS spring (probably to allow it to meet the legal power requirements of most markets in a single 'one power suits all' config).
If you're leaving the rifle at its out of the box power levels consider swapping out the hop bucking for something bigger and softer (eg guarder clear bucking). If you're upping the spring to 400+ give the original bucking a try