I have a shelf full of spare AC compressors here. You're welcome to one.
Great to hear - not often someone expresses concern about their engine running too cool, ad even rarer for them to find (and fix) the cause!!Problem solved folks, with a new thermostat and sliding seal. Back to a steady 85C or so once engine warm. Thanks to all for your considered replies and support. A/C also functioning after replacing throw-in coil on compressor