Hi guys,
A note:
The neon light in the turntable is used for stroboscopic adjustment of the plate's speed.
The neon light will "flash" twice in each cycle (both on positive and negative parts),the "bumps" on the plate rim are made in accordance with that.
Here is a circuit that can replace the neon lamp with 3 LEDs,
a bridge rectifier and a resistor.
It will tap into the bridge on the secondary (around 12V peak AC).
Use a small rectifier bridge, 3 high brightness 5mm blue color 2mA (or 10ma) LEDs.
for 2ma Blue LEDs use R=1.5K resistor.
For mounting the LEDs should be glued together.