Rolf Wiso's locomotive databaseRolf Wiso's amazing database can answer a lot of questions. The history of almost any specific locomotive, i.e. Depot allocations, boiler changes, rebuilds can be found here.
http://de.geocities.com/rolfwiso
Well, it looks a stunning piece of work.
But alas EUR33 to find out about 10-12 locomotives seems a bit expensive to me. Maybe next year :8)
John