The wire from the points in the distributor goes to the negative on the coil. A coil (all round canister coils) actually have 3 connections. 1st is the High Tension lead that goes from the middle of the coil to the middle of the Dist. cap. The other two are the low tension leads marked + and -. The negative side goes to the points, and the tachometer. The positive side goes to the ignition lead and the starter solnoid(spelling?). The lucas coil appears to have 4 connections because the + and - terminals have adaptors on them to allow 2 connections each. You need to remove these from your old coil and place them on your new coil.
Hope this helps
-D.