Hi Craig.  While I know next to nothing about serinettes, I _do_ know
that your friend had better be careful with the spring in the motor.
If he's uncomfortable working on flat springs, have him locate a clock
repairman as they are usually equipped to safely handle springs of
whatever size.  Also, the repairman will be more aware of the
requirements of 'setting up' the fusee.

Regards,
Bob Loesch