Thanks!!!

Here's a quick rundown:

• printed all parts in PETG
• Sprayed all parts with multiple liberal coats of sand and fill primer
• sanded things down with disposable nail files (wasnt too finicky, mostly wanted to smooth the box part and get rid of some bad layer lines on the posts)
• wiped everything down to get rid of the dust (i sanded only a few hours after spraying, so there was hardly any dust anyway, but just to be sure
• based coated all parts in metallic gunmetal (sans "neon")
• heavy metallic silver dry brush over most everything
• assembled it
• dry brush stippled dark rust around most the rivets/edges, and anywhere grime would settle (way easier to tell where that would be when its full assembled)
• Dry brush stippled bright orange rust color over top of the brown areas where corrosion would be worst
• came back through with light silver dry brush in non corroded area (i got a little overzealous with the dark rust color)
• used a homemade oil wash (black and burnt ochre oil paints mixed with some mineral spirits) over top of all the gears, and ran a heavily loaded brush along the top edges and over rivet, letting the wash drip dpwn the sides.
• after it dried for 5-10 minutes, i used an old frayed brush to lightly drag the wash down to make the big drips look for natural
• After i was done, I realized i overdid it a bit again, and went back through with some mineral spirits and cotton swabs to re-expose some of the "bare metal" in the centers of the panels. I love oil washes! You have a ridiculous amount of time to manipulate the paint before it dries up, and looks terrific after it's dry.

And there you have it!