"If I remember the pictures of these copy 2892's, the dead giveaway was two items, one the ETA 2892 is left sprung, which means the hairspring direction from the stud is towards the left, the picture I saw showed a hairsping right studded... and the other giveaway was that the stud and regulator were not ETA. ETA uses removable studs and regulators, whereas the Asian ones are riveted...
Haven't seen one first hand, so I can't comment on quality or workmanship.
RG"
Regards
Gunnar