That would depend on what the graded condition was before the re-blue and how well the job was done as well as the configuration. It could be a standard rifle, sporting rifle, fancy sporting rifle, extra lightweight rifle, carbine, or trappers carbine. Most of these variations also could be solid frame or takedown models, have various length magazines and barrels, round or octagonal barrels, special sights, different shaped buttstocks, and probably a few other variations I can't think of right now. If the gun was not over-polished before rebluing (all corners still sharp, all lettering still clear, screw holes not dished out) it would still be quite desireable to all but the most persnickity collectors. If it needed to be reblued, it certainly wasn't in NRA Excellent condition to start with. One of my references has a "rule of thumb" for relative values in varying grades, and it assigns a .85 to Very Good and a .68 to Good, so that would mean a reduction of 17/85 or 20%. To get an idea of what antique Winchesters will sell for, visit www.antiqueguns.com and browse the auction pages.