Those dark spots, I want to dismiss it too. But if it's some hazardous growth, I'll have to do something about it. Otherwise, I would not have mind as it doesn't affect comfort nor aesthetics. In fact, it's damn comfy.
Where do you get your cleaning accessories? Do you fit your footwear with boot/shoetree too? I'm looking for Red Wing cleaning accessories particularly for the 3140 and a suede cleaner.
Can't tell from picture what were those dark spots. are u able to wipe off the dark spots with warm water or cleaner? Anyway don think they are hazardous.
Most of my redwing accessories bought from ebay. The redwing wing stores in singapore seldom carry most of the stuffs. Ocassionally, they will bring in some creme, suede cleaner and leather dressing. U can call to check with them. Dono why, the redwing suntec uncles always recommend mink oil
I don't use shoe tree at all, cause i want my boots front to be curve, lol

Anyway, when I don wear them, I will stuff in old news paper inside the
shoes. Tips: old newspaper is good dehumidifier and helps to maintain the shape.