I'm trying to find where the a Duchess is - I have a kit built Duchess to strip and rebuild as it happens.
I'm looking at refurbishing 'your' coaches later this year. The paintwork is still in excellent condition but buffers, corridor connections, etc, have signs of wear.
The biggest issue is axle bearings being mounted from the outside of the bogie frames within the cosmetic axle box castings and these can fail so we need to address this.
We estimated that they have done over a six figure mileage! Perhaps quarter of a million miles.
They have incredible durability.