In Stereomour, the inductance from the blue wire (plate) to the black wire (tap for B+) is nominally 20 henries and can handle 55mA; DCR is 535 ohms.
In the SEX amp, or if the Stereomour is converted from 2A3 to 45, useing blue (plate) to red (B+), it's 40 henries at 40mA and 750 ohms.