Well, for my two cents, one has to assume that major companies still have the master tapes to all of it - they usually don't like to go from vinyl sources, and a lot of tapes get lost or degrade beyond usability.
As for leasing catalogs, ECM is owned by Universal, so I can imagine that might be quite a headache. If you can, I suppose you'd want to deal with the artists - though some of them are as out of it and loony as the labels...