Hi Nigel, the camo pattern on the tank looks fine. I don't know what your paint situation is over there, but the colors could use a little fine tuning. The German base green was a bit darker and the yellow needs a little brown mixed in to tone it down some. If you want to stick with what you've already done, a dark wash may do the trick of both, toning it down, and pulling it all together.

It's hard to tell from the pictures, but the build itself looks good.

Hi looks great. German paint has been debated up and down the block so I think about anything close is fine. A filter would tone down the colors and give a uniform look to it. I think a filter is twice as diluted as a wash would be. If you're using acyrlic paints on the model be sure to use enamel based products for the filters and washes (or vice versa). Have fun . I did one of these too I think you can still see in my photos.

And black enamel or oil paint for the pin detail washes. Be sure to use the correct thinner for the type of paint you use