Looks like a KG, but could be a CT, VT or Machin's Mills piece. Beware the peroxide as it can remove the detail of the coin along with the crud. I've seen it happen way too many times. Some coins with a smooth, hard patina come out great. Once you get a bit of corrosion on the coin it's a whole different story. My best success with old coppers with corrosion is just to rub the dirt off with you thumb. No water or anything. Indians and 2 cent pieces are different as you can scrub them lightly with a scouring pad. Old coppers can be delicate.