It has been eluded that the Torii III is optimized for the the 6N1P tube, and possibly that Russian tube has slighly different operating parameters the the 6DJ8 or 6922.   Is this so?  I know that certain other Russians are similar but require circuit changes to allow them to work and extend there life.
 If this is the case it makes shoping for NOS input tubes for this aplication a little less desirable because if changes to optimize the 6N1P could might not be quite correct for NOS Mullards for example. NOS or not?

Steve -

Does the same apply to the SE84C+?

Mark