The tracks are great! No fit problems, and a far cry from anay of the kit tracks out there.
In terms of painting and weathering, look at your reference photos and try to match the metal color as best you can. After you do that, take a Sharpie marker and color all the pads (it has a sort of purple shine to it when you do this, but after a coat of dullcote it's black). Apply dullcote. After this, use some pastels (again, depending on the theater of the tanks, usually either a brown or light tan) and lightly scribble over the pads. Take a thick, soft brush and brush off excess/blend the pastels. When you are happy, lightly spray some hairspray over the tracks, but remain at least a foot or two away from them (too close and you risk blowing the pastels around.)