I've neither a Mk2 or Mk3 so can't comment specifically on wiring but I do have experience doing something similar in an old Corsa. Typically If the wires are the same and only the connectors are different you can splice them together, before doing that you need to make sure the battery is disconnected and if possible disable any airbag system (this will likely need reset afterwards).
Another note is that messing with your airbags can invalidate any warranty or insurance claims, so you need to think carefully if it is worth the risk.