Gary,
I started with the Rust base coat made with spray paint as described in my book (funny, but I actually started this model a few years ago!).
The green shades were made using Grimy Black and Reefer Yellow initially, but I was also mixing Undercoat light gray. I don't really know what I ended up with - I just mixed and mixed until I gave up ;D Serious ;D But follow up with the GWIX treatment.
The colors I was complaining about a few pages back was probably iteration 1 or 2. ;D
Now that I'm finished, I'll unsticky this thread and find something else.