Step one is to verify the coating is actually gold. I'd add one drop of hydrochloric acid to the surface--if it's gold, absolutely nothing will happen. If it's some other yellow coating (chromate passivated tin is an option) it will likely dissolve.
If it is gold, a cyanide leach should remove it without touching the copper, but cyanide is unforgivingly lethal, and hence not a good first chemical project!
Have you considered using a belt sander or angle grinder flap disk to take off the outside gold layer, and collect the dust? It will remove some copper as well, but acid separation would be straightforward from there.
If I'm doing the math right, the front and back of a 1 inch wide strip 28 inches long has about $1 of gold per microinch of coating thickness (I asked google "1e-6 inch * 2 inch * 28 inch * 19.3 g/cc * $2000 / troy ounce in USD"). So even assuming a thick 25 microinch hard gold coating, you might not come out ahead if you need to buy the tools and materials to do this safely.