Hi Guys. Can anyone tell me anything on this balance wheel with white hairspring. Is this correct? Or is this balance wheel has been installed later? I have recently purchased this watch from a watch collectors estate. I really like it, and I wish I knew more about this movement. Like how many where made, and if this is a nonmagnetic watch? I do know it has missing screw. Thank you.

Photo of the movement.

The white hairspring is correct for the uncut mono-metallic balance wheel, however I do not believe either were original material for watches of this vintage. I think these may have been available much later as replacement parts.

Sham

Here's a link to two 21j that fall just on either side of your mvt you can stare & compare. This is in the time keepers photo area. These are extremely nice mvts and seen less often than the 23j versions.

https://ihc185.infopop.cc/eve/f...6047761/m/9791061242

Production numbers: 1400 open face, 800 hunters.

Charlie

Dear Jerry & Charlie. Thank you for the info. I would think then my balance wheel has been replaced. I do have a complete 1899 balance wih hairspring, do you think I should put it in to match the other 2 watches?
Thank you in advance.

Some Mfr's marked the serial number on the balance wheel arm. I would check the balance to see if the serial # matches the movement, and if not, change it out.

You may want to research it further before doing anything.

Hi Charlie, The serial number does match under the balance rim. I am lost now.

At this point there is no replacement that would be absolutely correct (because of the scribed serial number on any replacement balance wheel), but the matching numbers on yours does suggest that your watch may have been sent back to the factory for a replacement balance wheel during the 40's or 50's. I would recommend keeping it as is. [.. a blue hairspring would not be correct .. ]

By the way, the dial is an early Maximus dial, so it is unlikely the watch was merely finished years later, although as Lindell says this has occurred. However, when the factory was in operation one could send a watch back for upgrading or replacement parts. A simple switch or replacement by a watchmaker would have been unlikely to include the scribed serial number.

Thank you Everyone for the input in this matter. I am going to leave it alone, and keep it in my collection for a while. I love the watch and the time it keeps. I do think that I will put this movement in to a gold case or a salesmen case. I will enjoy it either way. Thank you again.