We recently had a guy buy one that was more than likely ex mines, the chassis was badly rusted on the inside even though a cursory inspection on the outside looked ok (it had been blacked). You should be able to tell from the service history where it was from and what has been done. Good luck with your search and be pedantic in each investigation, don't be afraid to ask why they are selling if private, your investing considerable money.What sort of things might tip me off that it's ex mine? It is a white DX.
I'm thinking I look for fine dust, but not sure what else to hunt for.