FWIW...
I built my own by making a very small aluminium "L" bracket to hold the 3 mm (solid red..not these fancy, clear, hi brite ones) red LED
& bolted that into the rear of the tube facing the objective lens. (Front.)
Drilled a small hole for the thin fig 8 cable & Bob'syeruncle.
Runs off the main t'scope 12 Volt/7AH battery but used dropping resistor to kill the current to ~3 or 4 mA.
Just a nice dim red glow inside.
Works fine.