[melt]

I have just put a 6119 balance into a 6309 and its swinging well and keeping good time.
I bet the rotors will swap but not the winding plate. Will the bridge swap with all those extra jewels to enjoy?
Any other parts that I can swap on these and other Seiko models please.
Thanks

 

[swedefreak]

This is a true case of "close enough" works. Generally not a good idea when working with movement parts unless there is a Seiko-provided substitute part number.

The 6119 balance is part #310 611, the 6309, #310 601.

The only sure way to determine interchange is with a Seiko factory issued Parts Interchangabilty Manual which can be found on the Bay from time to time. Anyone even remotely serious about preserving their old Seikos should get one of these, preferably from 1976 or 1978 as these contain most of our favorite vintage movements.

The various material house websites are frequently not up to date and contain large number of errors thus making them only "rough" guides for part numbers.