Most train cars are made from styrene plastic. Tester styrene plastic glue ( in red tube at Walmart or local hobby store were it is sold for building plastic models) will repair the parts by welding the plastic parts back together and should be as strong as before the break. The glue is clear and repair will be like new but will show as small crack. You can tell if the plastic is styrene by scraping the paint off a small area on the bottom of the car or inside the body shell, putting a small amount of the styrene glue and then scraping the spot with a knife to see if it attacks or melts the plastic.
Charlie
