Quite a story this. I purchased two MBA kits from supplier at an Exhibition. This was way before Dapol and Bachmann models appeared, Oh how I wished I had waited. When I got the kits home the resin castings were terrible, they were warped and twisted beyond use. I tried to straighten them in warm water and put in stretchers, but all was to no avail. The white metal casting were of reasonable standard. At this point I decided to cut my loses and scratch build the wagon bodies. The one advantage I had was that I had all the dimensions I needed on the mis-formed parts. On and off it took about a month to make the two bodies. I then married the bodies to the white metal parts, I then painted and weathered them. I had already decided that these would remain ‘stand alone’ and would turn them into scrap wagons.
Just before this exercise, the supplier ceased trading, so there was no way I could seek a refund.
I filled the wagons with metal filings to represent shredded metal waste, this was a bit overpowering so I dulled them down with various rust coloured paints.