I have had a TL3 for a short time now and I am finding it pretty awesome for its size. Also running 2X17500's. The TL3 is a real thrower with some adjustment available to the beam, as you probably know. It is sort of a mini M3T. Some people are running a 2amp bulb, for even better performance.
But I digress, as you are looking at it for an LED mod. It does have an excellent reflector and would probably work well with with a Seoul P4, if you could figure a way to stuff it in there. I could see someone designing a module that would take the place of the TL3's bulb holder, and there would be good contact between that module and the body if the module was made out of brass.
Bill