This is the washer for 36 to 48 springer front brakes. Early ones were not plated and left with a natural ground finish.
This is the washer before I took .003 off of it. You can see the original surface grinder marks on it. This is a cool detail. Other pieces that Harley didn't plate and left natural finish include chain oiler screws, dowel pins for cam covers and dowel pins for transmission tops.