Alright mate
black smoke = overfuelling
Personally if you fuel and a spark my money is on the metering head being fucked. The battery leads getting hot doesnt sound too good however, is it turning over well? Good starter motor i presume?
You say its been offroad for the resto, have you adjusted anything like the idle screw on the throttle housing? Or the mixture screw on the metering head? Something else to check, IIRC, when your cranking over you should be able to see the flap on the metering head moving, going up and down slightly (because your cranking and its not fast enough to keep a constant vacuum pressure in the inlet manifold), if you cant see it moving that to me would suggest an air leak? Also check you havent left any of the little wires off the battery terminals, very easy to miss off ive done this before
Im familiar with the wiring on these aswell, but i doubt it is wiring.
let me know if this helps and how u get on