Generally, construction lookks pretty good. You might want to check out a book with color plates as a reference for the figures. As noted, the commander looks off, but the loader's uniform doesn't look quite right to me, especially withthe helmet and jacket appearing to be the same color.
Did you paint hte headlights silver? Can't tel from the pics.
The one real constructio flaw I see is the second tot he last road wheel is floating. Does this tank have working suspension? Maybe the wheel is stuck on a guide pin and should be adjusted. If not, this is someting to watch for next time.
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When I do road wheels, which hasn't been for a while now, I attach the suspension with slow setting glue like Tenax 7R or Plastic weld or even Testor's bottle glue and place the tank on a flat surface, such as a piece of glass, to make sure the axles are all even. Then I let this fully cure before attaching the wheels. If the axles are higher than the bottom of hte tank, you can attache the wheels first.
Again, not bad for a first effort. Keep up the good work.