Where about are you in N.E Scotland at the moment? I don't have a spare sensor but I do have a shed and tools if you need, it's not a big job once you have the offending article itself!
Been away for a couple of days camping and just back or would have replied sooner.
Or, get in touch with 'Keith Garage' (01542 882501, & in Keith strangely enough), Les (the owner) isn't there at the moment but he does keep various spares and the mechanics might be able to help out, worth a shot?