They look similar, though they are not in any way compatible.
A regular Mag D head will not thread down onto a WL Torch. The WL Torch does not have the "mag-action" threads, it's straight up and down, on and off.
The bezel from a regular mag will also not screw on so no sleeper option there. The tailcap is not interchangeable; the body of a WL Torch is wider.
With the WL Torch, you are limited to stock body parts, though you get a fluted head, and a tail switch that gives that nice short body. There are things you can do simple and cheap to get your throw.
Get a different bulb for throw, one with a Vertical Filament such as below. You need to maintain a larger opening for a larger bulb, any mag sized reflector will work, such as an inexpensive Aluminum OP with 15mm opening.
For a bulb, I've tested the 62138 to 15.8V, though your results may vary, as LuxLuthor's test shows he got less but it wasn't in a Torch when tested. This may be due to resistance in the Torch, or I happened to have had a more robust bulb. Do be careful because the pack can be well over 17V right off your charger if using a regular or WL smart charger.
http://i61.photobucket.com/albums/h75/pike444/bulbs/62138.jpg
FYI I found with a SMO reflector this beam was too tight for my taste, so switching the OP reflector opens it up and still gives a great amount of throw, much over the stock 64623 bulb, though you will lose some of that flood you don't like so much :thumbsup:.