If you have ever owned a gun with a case colored receiver, you probably know that the case color can be damaged to out right obliterated quite easily. It does not take much to destroy it. I have a Marlin 1936, 2nd variation - B prefix, up for bids over at GunBroker.com and I am hopeful that the amount of remaining case color will be it's number one selling point. I have seen some other specimens of this same model sell for around the same price to some selling for much more than I am asking and they had zero remaining case color.
No, the case color is not perfect but there sure is a lot of it remaining on a rifle that was manufactured in 1941 (as best I can determine). Someone took rootin-shootin good care of it and I did likewise once I bought it. It, by the way, was another acquisition I made from the Hessney Auction Co. LTD of Geneva, NY.
All the best,