Mag 2-C, 3 x 123, Carley 1499 potted bulb, Carley 1940 LOP custom-run reflector, stock switch, stock lens. Shim bulb to desired beam pattern, leave alone.
Rated at 385 bulb-lumens, estimated 250 torch-lumens, IIRC current draw is 1.8 amps. Stock lens -seems- OK, I haven't gotten around to putting a glass lens in place. The stock reflector with a CA1499 will hold up for short blasts of light, but is a little bit past the accepted modder limit of 10 watts output for a stock Mag plastic reflector. Run time is a bit less than an hour.
The Mag xenon 6-cell bulb would be easier to find, but a LOT less output (around 60 lumens). A 2-C with 3x123 and a 6-cell xenon bulb is the output of a 6-cell Mag in a 2-C size with a slightly flatter discharge curve due to the lithium cells instead of the constantly decreasing typical alkaline discharge curve. Running a 5-cell krypton Mag bulb will overdrive it a bit and whiten and brighten the output compared to 'stock' drive levels, but beware that xenon bulbs typically don't like or tolerate the same overdrive levels that a krypton bulb can.
The stock switch can handle that current draw OK. It's not the voltage, but the current that is the concern with our usual flashlight operating regime.