I don't own right to share some of those bitmaps but from left to right:
Composite of bitmaps (Scratches 1, Scratches 2, Fingerprints ), each is slightly differently tiled to avoid tiling repetition. Also flexible to change each type of scratching without need to create one super-texture in PS and tweak it forever.
Output so I can adjust how much glossiness it will yield.
In the falloff node I mix the composite with clean color in front angle slot, so I can flexibly adjust the ration between scratchiness glossiness, and clean glossiness. In the grazing angle slot, I have pure white color. Look up Dubcat's guide on this forum for this. He has nice explanation of it, although I've seen it first 5 years ago in Alex Roman's video tutorial :- ).