On checking the coolant several times, there is no loss - also had friends to help me check and all felt the same.
No signs of excess smoke from the exhaust.
No, I do not recall hearing the main fan kicking in when overheating occurs.
Please note the car is not from 1956 - it was new and registered in Sept 2006.
Parts/testing/checks upto now:
A/C not working since 2/10/ 2010.
18/10/2010 Water pump and cambelt changed, water pump repair kit, bolt, v-belt, drive belts
30/7/2010 no faults experienced but coolant temp sensor replaced.
27/5/2010 Cooling system checked, pressure tested, thermostat and cooling fan operation all OK and not faults present.
26/3/2010 Thermostat seal and housing replaced.
28/9/2011 Water header tank fitted.
7/6/2012 New clutch kit and front brake pads.
Hope this helps - I have kept all my paper records in date order and have provided this information from all my file paperwork.