Has anyone modified their free dd light?

I just saw this light last night in my junk box and was gonna try dropping the ex10 r2 led in there. i hope the stock single mode driver works.

just got it done, 1.2a on 2 alkalines, used the old led star inverted as extra heatsink. we'll see how long it lasts.

tried 1 imr14500 and was getting >4.5a seems too high. overall im happy with the result. can't beat free.