Phil, the way I understand it is: if you have to get the clocks replaced (like under warranty etc) you have to take your existing key (red) to be re-programmed 
to the new clocks.
 It is worth looking for a set of replacement clocks, to keep as 'spares' for just in case.....?? 
 Otherwise, use the keys with that ignition only, as coded to it
  I could, as usual be totally talking out of my backside tho
  C