Sounds good Gj. Thanks for reporting. Do you know if your light has the capability to run on one cell? You probably already know how to check. Just in case, you can find out by putting one of the DMM probes down in the tube to reach the cell and then touch the other probe to the tail of the body (with the DMM in current measuring mode).
You all probably already know this too. If your drivers look like the one in this thread, you can add resistors on top of (or in place of) the resistors shown in the picture. Your driver may also look more the one in the third pic of the OP. Both use the same resistance values to achieve desired current to the emitter.