These should provide a similar sound at much less cost. They were recommended by Chris Johnson at Partsconnexion:
http://cls.audiogon.com/cgi-bin/cls.pl?accstube&1138768685
http://cls.audiogon.com/cgi-bin/cls.pl?accstube&1138768685
Leads on mid-1960's Siemens NOS CCa 6922 tubes