Great subject and not a bad likeness.
But if I might suggest kindly, I think this needs a little more work, which I presume should be possible since it's all on the computer at this stage : as Harry points out , the webbing on his back is wrong, the braces should feed into two buckles on the belt. The Sten should have a forward pistol grip as well, which he would hold rather than the magazine. And perhaps you should look again at his legs & feet : they are enormous relative to his torso . The ribbed cuffs should be much finer , and perhaps the smock is rather short overall.