If it won't idle down make sure the float needle is working properly and not pressurizing the bowl . Also, verify the throttle plates are closed and one isn't loose or something weird . Test the fuel shutoff solenoid , they are pretty universal and if I remember correctly share the same type as some of the US made Escorts . Carb icing is from cold damp air freezing within the venturi's , or water mixed into the fuel becoming frozen the same way . A warm air box or heated air pipe off the manifold like the stock setup will cure this ....
Sarge
Sarge