For very helpful guidance seek out vendor Jim McShane who resides mainly at Audio Asylum and on the net as McShane Design. I have had excellent results with him and his voice is well respected on the Tube Asylum.
No financial incentive, just a happy customer etc.
BTW I don't know how much the Brimars cost but I can't blame you for your interest in them. I have finally stopped chasing small signal tubes (pre-amp tubes) because the prices for NOS and experimenting has gotten too expensive. The rich, full sound that the old Mullards have, is I understand, now found in the Gold Pin version of the Gold Lion re-issue 12AX7 equivalent (B759 I think.
No financial incentive, just a happy customer etc.
BTW I don't know how much the Brimars cost but I can't blame you for your interest in them. I have finally stopped chasing small signal tubes (pre-amp tubes) because the prices for NOS and experimenting has gotten too expensive. The rich, full sound that the old Mullards have, is I understand, now found in the Gold Pin version of the Gold Lion re-issue 12AX7 equivalent (B759 I think.