My "NEW" HSR25s arrive with engravings (and some even scratched out and rewritten) on the bottom side of trucks in corners. Obviously hand engraved.
Engravings such as C0 and -2 and 762 on 3 of corners of all of them and then each with a unique 15M,27M,30M,38M in the last corner.
I could blissfully hope this is some kind of factory measurement but I have my
deep doubts.
Looked at ball raceways under a 80 power scope and things look real clean but I'd imagine they could appear that way if they were from a silicon fab or medical enviro. Didn't see any obvious ball scoring. No detectible play in bearings but I doubt I could feel that with just hand applied force.