This is an OUTPUT transformer made by STANCOR corporation.
This transformer was pulled from an amplifier that drove a 6L6 power tube.
I have also made a 6L6 GC SE tube amp with this transformer and it works well doing that.
The primary impedance is 5.3 k and there is a 32 ohm and an 8 ohm secondary.
Center to center the mounting holes are 3.1 inches.
The iron is 2.6 inches by .7 inches by 2.2 inches.
Winding are 1.7 by 1.4 by 1.6 inches.