I have found out where the resistor lies, its right below the front valance where the wipers are, but I hasten to add that accessing the resistor has taken off a few years of my life, since I started by removing the dashboard. On well!
Anyway, the resistor was not damaged but was not functioning as the entire valance area was flooded with water, causing the circuit to short out. Hmm, i wonder how water ever got in there anyhoo. Any clues??
Sure hope that this tip is useful for anyone having the same problem as mine. Anyone out there with a spare W123 aircon resistor?? Sure appreciate one to replace my corroded one.