I bought a RRS Anvil off here a while back. The handle looks very similar to yours. I oiled it all up and do when I use it or it gets wet. It doesn’t bother me as it’s equipment. But oddly it’s basically the same condition as yours
RRS should be nitride for the price, maybe even gold plated. I have one that's got a bit of corrosion, but not at that level. Funny thing my Sunwayfoto head is 2 years of being in the back my truck bed, and it appears near as new, go figure!