Fantastic freehand. It would be nice to get some simple side on pics to get a good look at it rather than trying to work the angles into the design. It is a bit hard on the eyes when looking at detail. Having said that I would love to be able to freehand like that no matter what angle it was on.
Whilst the paitning overall is good (from what I can see of the not so good photo's ;) ) I think you need to practise your weathering techniques a little more, as the scratches and weathering on this look more like camouflage thay are that randomly done.
If you have a look at some of the historical miniature site, or even pictures of old tanks etc, you'll see the scrathes and dents tend to appear on specific areas of a vehicle, rather than all over it. But good luck with your next go!