Legendary Verion (Cotter) Step Up Transformer Mk 1, type P (for very low impedance cartridges: 2-30 ohm)
Working perfectly - cosmetically shows wear.
Tested: see frequency response of both channels (1st picture: left channel; 2nd picture: right channel): effective bandwidth > 75 kHz. Frequency plot with device output not terminated with 47kohm resistor which may explain the peak at 75kHz.
Configured for 24.2dB gain (16.28x gain): valid for very low output MC cartridges.