FastTech has shink wrap available for 14500 cells here but only in yellow:
http://www.fasttech.com/products/0/10004244/1140202-23mm-heat-shrink-wrap-1-meter
The wrap shinks to the same thickness as a factory wrap... If you remove the original wrap and replace it, your cells will be approx. the same diameter. For details on using the shrink wrap, check out GottaZoom's process here:
https://budgetlightforum.com/t/-/14650
This shrink wrap works great with a hair dryer, no need for a heat gun or flame...