Part/ Info ladies bubble back Oyster perpetual
 

I recentlu found a ladies oyster perpetual bubble back. My watch guy says behind the dial is the number 6100 and he thinks it says size N . I am trying to find a balance staff at minimun or a complete balance assembly in a perfect world. I think this makes it cal. A260 thats just what I have been able to come up with .To even inquire about a band would probably be beyond all hope but I will throw it out there anyway. Any and all help is appreciated if its only to find the part number .. Thank you , Ed