Air -brush the white stripe over the turret and the hull, then I hand-brush it to simulate painting done in hand in real vehicle

Applied raw umber for pin was.....when the oil paint is dried, will do some paint chipping and scratches.....

Ah, jeez, as Archie Bunker would say. This is looking so very good and your going to risk chipping and scratching? 2 of the 3 most over used "weathering" techniques? Can you tell, I'm not a fan? IMHO, in most cases, probably 90%, these techniques, along with pre-shading, reduce the realism of a model making them look very, well, "modelistic."
The one thing you might want to really consider is shifting the fording log to a gray color. Exposed, untreated wood turns gray very quickly when left to the elements.

Nice job on that Trumpeter kit. I agree with Al. Not a big fan of chipping or scratches either, although I do it on occasion. Nothing is more imposing than a big green T-55. (I saw my share in the DDR) The stripes make it all the more so somehow, and they're very nicely done.

Very nice progress Mike! Do weather the tracks a little. Dust them with pigments. It'll look great! Keep us updated.