Rustbucket GP35 of the NWP, weathering help

[engineshop]

For the background of my layout, I like to do a GP35 NWP (ex SP) as seen in this picture

http://ncespee.railfan.net/Foothill/images/nwp6595.jpg

I am using a Atlas GP35 shell, trucks and fuel tank but nothing else. It will be a static model just waiting to rust through.

I have been weathering freight cars with powder but I have never done anything like this. I was wondering if I should paint the SP paint scheme as it would be new and start the weathering from there (washes and rust powder) or if I should try to get the faded gray and red somehow with mixing white paint into the mix.

I have read Tom Mann's method of painting the models rust color and than using salt but that might be beyond my capabilities to make it look real.

Thanks for the help

[tom mann]

I would only do the rust/salt on the blower duct and sill.  It would be overkill for everything else.

Paint the duct rust and then salt the bottom and side.  That won't add too much work but will be a nice touch in the end.

It the top is worn-away grey paint and the lighter grey primer is showing, I would also salt that.

[engineshop]

Tom Mann
Thanks for the tip. I did not even think about the roof section and the faded gray.
Luckely you mention it and I found this one of an SP locomotive roof that gives me some ideas since there are not other pictures of the NWP engine I could find.

http://www.mindspring.com/~mszeni/SP9607-2.jpg