At Brent Jesse for you purists (with $$).
http://www.audiotubes.com/12ax7.htm
caveat: I'm not associated with these guys but have been a customer.
"The finest Telefunken diamond mark smoothplates, NOS, in whitebox. Very fine tube, in great demand, especially this smoothplate version. Fair to excellent labels on those with labels. Save big on these as some are made for Dynaco, some for Fisher, some not labeled. All are the real deal, with the diamond mark in the bottom glass"
http://www.audiotubes.com/12ax7.htm
caveat: I'm not associated with these guys but have been a customer.
"The finest Telefunken diamond mark smoothplates, NOS, in whitebox. Very fine tube, in great demand, especially this smoothplate version. Fair to excellent labels on those with labels. Save big on these as some are made for Dynaco, some for Fisher, some not labeled. All are the real deal, with the diamond mark in the bottom glass"