I've got a CroMo frame which has picked up many scratches over the years of use, which I'm in the middle of doing a re-furb. on. Not full blown, I just want to treat the scratches. I've put some rust cure on near the bb to test out and it's gone a slight blue but also a bit shiny. I don't really want to treat more obvious areas to shiny blue so what's the best way of going about things?