RadioGuy wrote:

I still have yet to find the production data of the 6146 (how many
manufactured)---my two hour long Google search still has come to naught.
Similarly, production data for the 6JB6 (how many manufactured) has escaped
me as well and would be of additional interest in this running thread.

It might be tough to find the data on the total number of 6146's
produced since RCA was not the only manufacturer of the tubes. RCA,
Sylvania, GE, at least one Japanese firm and possibly others produced
the tubes. Likewise, a number of manufacturers produced 6JB6's.

Dave K8MN