Mondeo ignition lock jammed

remove the whole lock and take it to a locksmith

That's the point, he can't remove the lock. Even if he took the whole steering column off, the lock would still be buried away inside it, apart from the face where the key goes in, so would a locksmith be able to do anything with that?

In the past I have taken other jammed lock assemblies into a local locksmith and they have known just where to drill to release the barrel, but not an actual mondeo one. Perhaps you could have a ring round locally and ask a few, there must be some specialists that will have seen that exact job before.

He managed to hack it out somehow anyway, and he can start the car by holding the key near the immobiliser sensor and turning the switch with a screwdriver.

He'll need a new ignition lock obviously, I don't suppose you can get them made to fit existing keys and he'll need new keys too? The driver's door lock has been playing up too, so I suppose it would make sense to replace that at the same time. Can you get matching sets?

you can get the new lock built to the original key profile or buy a complete new set of locks with keys, the new keys will have to be matched to the cars electromic code.