question on discerning knockoff 2008 clones

im interested in getting a clone commander wolffe from bricklink or Facebook marketplace but I'm concerned I won't be able to tell if it's a knock off from redmill customs since I know a lot of older clones don't have the mark on helmet, or these companies print on official lego pieces.

does anyone have any tips or is this just a risk and you'll never be able to tell the difference?