Powerful Gordon Repair/swap.

[Super]

Now thats much better. They should come out with a series called "Angry Trains" and release all the Thomas & Friends characters with an angry face. I suppose they could also call that series the "Constipated Trains"

Now I am no chemist or scientist by any means but as far as the discoloring and being so brittle my guess its the affect of the Sun's ultra violet rays on vintage plastic. Back in the day the act of blending in UV protection into the plastic was not perfected, expensive or little known. In todays world it is more of a common practice. The plastic doesn't necessarily have to be in the direct path of the UV rays as they are all around us but being in the path would speed up the breakdown of the plastic. White plastic seems to be more susceptible than colored and you can see plenty of evidence of this in some white, older released Plarail trains or trains that were partially white. Maybe this sentence from a real scientist might better explain...

Plastic polymers in contact with UV light causes a breakdown of the chemical bonds. This causes degradation. The surface color fades and yellows and becomes dry and brittle.

Here is a recent video with a Powerful Gordon afflicted with the same discoloration but possibly not as brittle as yours Ripley. https://www.youtube.com/watch?v=XrnTHv3dmHg

Sorry...this Post sounds like a Science Class Lecture....there is the bell...class disnissed