This rotor weight recently came to me inside a Constellation ref. 368.0845 cal 751. The watch ran pretty good but this rotor looked out of place. I sent it to my watchmaker and he gave it a service and replaced the rotor with a correct one. He guessed it was a cal 550/560.

Could that be right? It doesn't look like any of the rotors I've seen for those calibers. Is it possible someone would have polished the rotor down to give it a different look?

It measures between 27-28mm diameter and there's some decent corrosion on the bottom. Hope someone can tell me what movement it belongs to.

 

Don't know what look they were going for but it has been polished to death.

 

Thanks. That's what I was thinking. But why would anyone do such a thing?

 

Probably to *try* and restore the rosy copper hue that was originally on the rotor.
Corrosion can push people to do interesting things.

BTW, the rotor seems to be a later 55X/56X/75X movement rotor - it's missing the additional elaborations around the rotor hub that give the early ones more of a decorative flair.

 

Thanks! I wish people would do less "interesting things" with vintage watches.

 

No problem!
Be aware though, the vintage watch market is a minefield with a lot of examples that have had very, very interesting things done to them.

(paperclipgate)

 

All the 550/560/750 series use the same rotor. This one has been modified by someone in the past clearly, but it was the "correct" rotor to begin with.

Cheers, Al