You would be hard put to find an Ampliphase still in service anywhere in the world today but there are loads of Doherty amplifiers, and I am not just talking about the likes of the Marconi B series at the BBC AM networks. There are Doherty amplifiers for mobile phone base stations, satellite and microwave links and digital TV and DAB networks and so on.
Ian, I am sure that Robin told me the RCA 100 kw was a prototype built in Italy.