Mraconi B65 tubes?

Has anyone ever heard of them and heard them? If so, what do you think of there sound?

They seem very pricey so I want to be sure of them..
Marconi Osrams or MOV yes I heard tell of them but more frequently the B39 I think which is the 12AX7. The asking price for a pristine pr of NOS B39s about two years ago was $1000/PR. That was a semi private offer. I politely declined.
( Mr M- You've found a 6SN7 that I've not auditioned as yet. I may have to sell an ounce of gold to try a pair.
I hate it when that happens! Then again: Brit tubes are always too warm/euphonic for my tastes. HMMMM!