Tt I recomend:
Some flat black exhaust soot from the exhaust area,spreading aft to the box behind it.
A rusty wash on the tracks.
Have you chunked the edges of the road wheels?
I think a Polish or other Warsaw pact vehicle might have some slight maneuver damage(scraped off paint,minor dents on thin sheet metal.) and should be only slightly shown on this one.
I can't wait to see the fuel hose connections.
(++) (++) (++) (++) (++) (++) (++) piggies so far.