Maybe you could find out from the Spanish CAA if the owners hold ATPL's.
The second Metro is sitting on the apron in the IOM rotting .
From what I can see nobody has taken it out of service (there is a decomissioning work pack needs done before the aircraft is stored) and nobody is running the engines once a week.
Anyway its pretty easy for the investigation team to find out because in theory the AoC holder should have training files on every pilot that flys under their AOC.