Winchester?
It's no doubt, a Winchester 52, but the Sleeve ( Top Cover ) hides the complete serial number. If a single shot adapter is used, then it could be an A, B or C model. Lots of work went into the engraving, but that Pink stock would have to go. If you can find out the serial number, we can tell more about the action.
PS:
After a second look at the photo's, it appears to be a model A or B. The action was sleeved and made into a left port. The sleeve could be hiding some imperfections. Trigger does look factory, but could have been modified.