Friend has Giga-Fire G9 he loves but would like to change it to LED.
It uses 6V Xenon and 6V Ni-MH 5x2/3A battery. 3x16340 can be used with no modification as tube is 2 part. Also I could make it work with 2x17670 I have spare.
It looks like the replacement bulb assembly is vaguely P60. It’s unlikely to be an exact match. Even if he could alter an LED P60 drop-in, the reflector shape would be different and the beam characteristics would change.
A replacement bulb is 35 € and 400 lumens. The same 35 € would go a long way towards a budget thrower of 1200-5500 lumens.