Just a quick bash, this one:
I substituted MTH trucks on this old Standard O gondola. This has the effect of lowering the car making it's appearance more prototypical.
I have standardized on this style MTH truck. Notice the hole in the car floor just above the bottom axle. That is the original truck mounting hole because Lionel built these cars with that odd off-center truck pivot. So I drilled new holes in order that the trucks and coupler knuckles are correctly positioned.
Lew