for the noise, you can stuff foam in the stock, accessing from the butt,around the mechbox.
if you ever need to take your AUG apart, here are things you need to know:
-always remove the magazine before removing the handle/barrel unit
(failing to do so will endanger the hop up, and also result in a bb shower inside the body if the mag is full)
-always remove the handle/barrel unit when removing the mechbox.Failing to do so might result in a broken internal nozzle on the cylinder head.
-the taking in and out of the mechbox is greatly improved by filing or removing the two plastic lips inside the stock, around the mechbox's butt, on which the internal buttplate rests.
-the port covers are affixed to the gearbox, be carfeul not to destroy them when removing the gearbox.
JG aug mechbox with the port covers on thop