I just picked up a cherry MK I 4 3/4" and according to rugers website it was made in 1979. Which would be the correct box for a gun made in 1979?
Red? Yellow?
As far as I know, there never was a MKI with a 4 3/4" barrel. IF it has fixed sights it is not now nor ever has been a MKI.
ALL of the MKI RUGERS are target pistols with fully adjustable sights.