The Atlas 4-4-0 cast stanchions are possibly the most beautiful, and damage-prone, part up there with the flagpoles and the whistle. You can't get the darn thing apart without pulling out the stanchions, and they snap easily.
I've always made my own from .010 wire using a tight wrap around a .010 wire core, snip, straighten. I've had to replace nearly every cast plastic stanchion I own due to breakage.
For 'tight' handrails, cut levers, misc. mounts I use GMM lift rings in stainless steel, disturbingly tiny yet durable.