Some shafts have characteristics that are distinct for a cuemaker. Of course anything can be copied and cuemakers make shafts that meet the specs for the prospective buyer. Mostly, it is a leap of faith. However, except for Searing shafts, most likely, you’ll be paying less than you would for a mass produced carbon fiber shaft. Shafts are poor investments and don’t substantially increase in value over time. So, if the price is right and you love the shaft, it’s origin is just a piece of lore that might be interesting even if it can’t be proven.