Funny, just yesterday I saw here in Germany a train where the locomotive was labeled 'rent me'. Apparently there's an organization which bought old locomotives (this particular one looked like 60s, maybe early 70s vintage) from the state-run former monopoly to rent them out (large industrial customers I'd think).

I was surprised to see such an old locomotive in operation, but apparently it's still good (i.e. economic) enough to shuttle cars from factory to port. Guess the air pollution restrictions aren't all that tough for diesel trains.

EDIT: didn't realize this is big business in Germany: https://railmarket.com/eu/germany/locomotive-rental-leasing