You will have to contact the Buffalo Bill Historical Center and have a serial number search done via the Cody Firearms Museum. They have original Winchester hand written factory ledgers from a hundred years ago which can be searched. Actually digital copies are looked at. Once your serial number is found the records may show when it was "R&R" which stands for returned and repaired. Usually/sometimes the type and extent of work is noted there. Here is the link.
http://www.bbhc.org/firearms/index.cfm
Good luck
2bit