I have to ask… Was there any work involved in reaching 14″ by 8″? Or was it just puberty and genetics working their magic?

A bit of genetics and a bit of ‘manual encouragement’. Difficult to know what was attributed to what, but I was a late grower and was likely to top out at 10-11, maybe 12 inches. All in all I probably added 2.5-3 inches by jelqing to end up at 13.75.