D.W. King sights: were King sights every factory installed on Model 90s as a special option?|Winchester Sights|Forum|Winchester Collector

I have an all nickel deluxe model 90 with nickel D.W. King front and rear sights. Were these sights ever installed by the factory on special order in lieu of the standard factory sights? The nickel on these sights appears to match the nickel on the rest of the gun with the consequence that it appears the sights may have been installed by the factory before the gun was nickeled. Sorry not to include photos but I don’t know how to post them. If anyone is interested in photos send me your email address and I will forward photos.