Okay the standard MT trucks come with a sprue with a pin, washer, and adapter for sing the MT pins in larger mounting holes on some models. Has any body ever used the adapter to repair a damaged truck bolster?
I've never done it, but it ought to work. Take care to ensure that the enlarged hole you glue the adapter into is centered in the car under frame.
My thought but wasn't sure about it. However I solved my issue in another way. Back when I was building some camp cars I had made some truck bolster molds and cast some resin bolsters, and I forgot about them. Old geezer brain finally remembered them so I sanded off the old cracked and chipped truck bolsters and ACC'd the replacements into position.