Well, 50 hours or so in, and the Seiko has already gained over a minute, so safe to say timekeeping of this old, unserviced example certainly wouldn't suit your requirements.
In any case, given Seiko's quite remarkable sample inconsistency, even buying new you are always taking a gamble: you may buy a good one that times well, has the hands/bezel/rehaut lined-up properly, &c, or you may not. QA doesn't seem to be their 'Thing' until you hit Grand Seiko level, where things go from the ridiculous to the sublime - or so I'm told.
Doesn't bother me, I like this cute little thing and it'll hop into the cabinet to be enjoyed sporadically