This is my second go 'round at weathering the tank.  I sprayed it with a military/camo green color, and set about with the dirt, grime, and rust.  I've gone back twice to expand upon the subtle effects, and would love to have some input/suggestions...I fel there may be more to be done.

Interior hatches:

Let me know what you think, and thanks for looking.

Wicked cool man!!!!  Those WW1 tanks have always looked pretty cool to me, and you are doing this one justice!

Brian

Wow, everyone...thanks for the very kind responses!  It's encouraging to know that other modellers think I'm headed in the right direction.  The treads DO need more...something.  I was thinking perhaps a metallic drybrush (perhaps silver and copper mixed) with some rust.  I've noticed on some models that the treads are all gunked up with mud...how is that effect created?

Again, thanks for the nice reception on this.

Taking some of your suggestions into consideration, I decided to do some further work to the treads.  First up, I masked off the rest of the tank:

I sprayed the exposed treads with a thin coat of Krylon Nickel...I wanted a bit of texture, as well as cut down on the opacity somewhat so that the dark green would still come through a little bit.  I then did a sloppy wash of a black/brown mixture, wiped away the excess, and took the raw sienna/rust color to the rivets.

And a black and white one just for fun:

I'm going to muddy up the tracks a bit, and add some more dirt and grime into the nooks and crannies of the tracks as well.  I checked out the Mig Productions link, and may try to engineer something a little more homestyle.  Would a plaster of paris mix, or perhaps some fine sawdust mixed with elmers work for a mud consistency?

Thanks again for the great feedback...don't hesitate to keep it coming if you see another issue.   

Thanks again, guys. 

Not sure of I have the weathering remorse about this or not...

I did up some plaster of paris mud, mixed with black and brown acrylic paint.  I tested it, and it dried to a lighter, grey-brown color that seemed plausible as dried muck.  I then applied it to the treads and some logical areas...I'm wondering if I have to go further, or if I've gone to far, or if the model looked better before.

I tried to add a bit of depth and color to the muck by applying a black/brown mixture, and then highlighting with some light tan/beige.

Looks Great!!!!!    I would suggest following your instincts on weathering.  If you start to not be sure about the approach you are taking I like to get some perspective and then come back  and look at it.  This IMHO is perfect that way it is.