Those look like the Monitor X Acoustats. They came with either the OTL tube amps or the interfaces that needed a separate amp. I have never heard them but from what I have read they sound very good with excellent imaging.
The link you provided is interesting as I did not think they were still in business. I don't speak German but the flag ship model appears to be the Chinese made version, the last ones I know of that produced Acoustats. At 50,000 euros I don't think too many were made. These may be NOS speakers from China. I'm not knocking China, that is just the last place I know of that made them. But if they are now being made in Germany again, right on!