So many of these types of tubes are out there as they were used in military radios. There are literally warehouses full of them. I am sure somewhere there is a large stash of Lorenz and Marconi's somewhere gathering dust!
I know the seller that sold me the Siemens once he found out there was a market for them jacked the prices up considerably! The Telefunkens I enquired about were DL92's but in truth they were re-branded Mullards so thinking on it I already have them!