Steve, I just took 2 days preparing 4 aristo craft passenger cars for kadees and “shaping them up”.
Tons of windows fell out, the kitchens in the diner cars all loose and bouncing inside the car, broken this and broken that. All fixable. When you have an HO model and your face is 1 foot from the loco, that’s where people strive for perfection, and close inspection is possible.
In large scale, you are many feet away, some of these small details will get broken, you surely are not the only guy with a broken step on his GP9!! I have 3 and all have had at least one step broken.
I’d counsel you to enjoy the (literally) big picture. Of all the scales this is easiest I think, just because of the size. You can repair stuff with blocks of wood, tire weights, etc.
Take a breather, run a train or two, even without windows. Enjoy yourself, and don’t be so hard on yourself. Perfection is difficult in life and is highly over rated!
Best, Greg