easy solution....
Use your RCR123s and simply replace the P60 with a P90.
Shorter run time, but no worry about flashing the lamp.
If you want to go the LED drop in route, don't waste your time with 2xRCR123s, use one 17670, and get a drop in that works at 3.7v. One 17670 will give way more run time than 2xRCR123s.
Post a pic of your light. Surefire doesn't make a light called the M95. It makes several lights with the part number M95x (ie the M951XM07, or the M952UM07, the XM and UM parts refer to the type of tail cap, the 1 refers to thumbscrew mount, the 2 has an arms throw lever).
Basically the M95anything is a 6V weapon light with a M2 head.