I combined two designs, (http://www.thingiverse.com/thing:1508831 and http://www.thingiverse.com/thing:734608) to form a bit of a (in my opinion) better flashlight mount, i liked both designs. However, i found the latter to be for a bigger light than i have.
The flashlight used for this mod is the same as the one in the picattiny rail design (http://www.thingiverse.com/thing:1508831). The mod basically uses the Arc Rail mount from the original ops core helmet design, and the flashlight section only of the picatinny design. As noted, i use this design on my airsoft marker as well, hence why i like it and trust it. In addition, i elongated the design with 5mm, as to fit the entire gap found in the flashlight, on my marker mount my flashlight shifted around a bit (not major), so i just removed all the play in the gap. (All credit to original designers)
It fits perfectly, i have made one, and it works perfectly.
The dimensions, for those that may need them are:
Inner diameter 20mm
total width 31mm
I printed with ABS (normal ABS Settings)
You will need 2-4 x M3 nuts and bolts to tighten the flashlight in the housing. (I only used two across, as 4 seemed redundant)