Older homes tend to use old knob and tube or copper wiring which can be dangerous in many cases. (mrhomeinspectorltd.com)
Old knobs look great and I've even used silver forks and knives as well. (countyroad407.com)
I would fully clean old knobs from all oils and kitchen grime (so the paint will adhere properly), sand the knobs a little bit to rough them up, dust them with a rag to get all the dust off, and then spray paint them with either a metal finish (like ORB) or spray paint finish (you can use a glossier finish). (theinspiredroom.net)