So, I toned down the rust effect with washes made from artists oils, mainly from mixing raw umber and black at several ratios. With that mix I also added grime at the lower ends of the boxcar. Everything was coated with acrylic mat varnish so the colors can withstand handling. With the tip of a lead pencil I added a light metal shine on the raised details. This was the last thing to do with the boxcar. It took alot of working hours to come to this result, mainly because I was trying new techniques and of course I was waiting for each layer and varnish coat to set so I could move to the next one. Meanwhile I abandoned - only for the time being - the idea of the Post-Apocalyptic dio. Perhaps in the future. Instead of that I created a small diorama for taking photos of my freight cars. More on that later.
The freight car SOLD on Ebay.