I've owned many of those in years gone by. There's always the possibility that I'm wrong, but if so please show me to be wrong and I'll plead guilty to 'jumping the gun' based on false assumptions. (It won't hurt my feelings! I learn something new everyday about vintage drum equipment.)
Quite often what appears as "brass" is in fact the copper plating applied to steel which is showing either due to age and wear, or due to being the area held when the metal was dipped into to the chromium plating, therefore not taking being well chromed in that area. I have presently a very heavy steel shell "Dixie" snare made by Pearl, which has a large section of the interior shell unchromed with a brass-like or 'orange' appearance demonstrating this. My drum, like yours shown in your photos, is dented where it took hard knocks along the years when it was either dropped or shaken around in the bottom of trap during transport.
I am posting a photo of the drum I mention as an example
By the way, I'm sure your drum sounds nice. My critique should in no way be taken as a slight of the drum's performance worthiness.