If the lower pin is intact, all I would need to do is to change the plastic Pin Cap. If that is the case, are your experts thinking that the replacement Cap would probably not be as good as the original, even if it is the same dimensions? i.e. different material and would not last. P/N 21-100 actually looks like it is exactly what is in the top hinge assembly currently.
Or, most likely, your experts know that when I remove the door and look at the lower pin, it will be destroyed, and oh well.
My plan is to identify a replacement door, complete. Then, take the existing one apart and have a look.
Happy New Year
Dave