Sight Leaf Finish

I just acquired a 1941 Lithgow in excellent shape. I'm cleaning it up right now because it is pretty filthy. My Skennerton and Stratton books describe the leaf but I can't seem to find what the proper finish is for the top side where the ranges are stamped. Was it in the white or blackened? Thanks

I believe it has a bright finish. Certainly British ones do and I've got some of those in grease. my Aussie ones are used but look like they are unparked and unblued.