Not sure about date of manf.

Can you guys decipher a little mystery for me? Got a 7548-7000, chinese day wheel (cool), all original components as far as I can tell, with a serial stamped on the caseback 853109. That seems to fall outside of both beginning and ending of production dates for this, do you think its May 1978 or 1988?

I think theres a problem with the stem and where it engages the clutch to release the hands drivetrain, I'll set the time and the hands (except for the second hand) wont move for 4-11 minutes, then follows along just fine the rest of the day. the second hand sweeps along fine, keeping time with a digi stopwatch, so its not the quartz circuit or batt.(?) the weirdest thing is I can set the hands ahead, and get close to correct time when everything catches up, then it will loose that 4-11 minutes again. I havent stared down the watch for 24 hrs, so I dont know how this happens. replacement 7548 on the way.

got any thoughts whether this can be fixed? Thanks all