as two above,

Air the system, go pop the kettle on and boil it while ur making urself a cuppa pop some in a bowl and put ur thermostat in, should open, I just repalced mine. Check water pump is working fine and if not change that, think when i did my water pump while i had my engine rebuilt it was something like 40-60 pound. not that exspensive.
also change the fan plug.

I run my fan on switch as the fan plugs tend to frie and stop working. just a switch in the dash so once its a bit warm. say 1/4 warm and im town/traffic driving ill switch it on. i wouldnt bridge the fan so its on all the time as it may undercool and thats just as bad.

That heat Sheald aswell,that chrome RSTURBOone. Get rid of that while driving the car, they hold so much heat.. i also removed the plates under the grills on the bonnet to push more cool air in and out the top of the bonnet.

Other thing, Bonnet lifters work..

nice car tho..