Stainless:
What I've done is to take a burned out SF Pxx L/A, remove the reflector from the rest, and drill out the center hole wide enough to accept a T-2 1/2 bulb.
I then epoxy the SF reflector to the front of the aluminum PR bulb threaded retainer ring that goes over the aluminum PR bulb retainer cylinder post. I use a Carley 912 PR base socket and plug in either a Carley T-2 1/2 bulb or a W/A T-2 1/4 bulb to the ideal focus depth. I've done this on my Nordic C lights, but it will fit on Mags with a considerable waste of space. I haven't tried trimming out the center of a Mag reflector to surround the SF LA and capture some of the side spill, but this is a future project after I kill some more SF LA's.
