Recently purchased an old Blenkhorn's axe head. I noticed some rust around the eye so I thought I would take off the handle and clean it up as much as possible. There were also some scuffs from grinding that I want to clean off. I decided to use vinegar to clean it, and this is after a day: It needs another day in the vinegar, I think, as there is still rust in the eye. And I wasn't really expecting this sort of colour. Any thoughts on what else I should do to clean it up?