Firstly, for your information the A/C lower port is situated at the right hand side of the O/S headlamp (looking from front of vehicle) within the front grill assembly. No need to remove anything has access to this is unrestricted.
Secondly, I know the history of the vehicle has I have owned it since 2008 with just 89 miles on the clock. I purchased this through a specialist dealer who re-imports vehicles from Jersey and Guernsey, so no VAT etc... This came from Guernsey.
Halford's have checked out the A/C and, as suspected, no gas pressure in the system. Their prices are, in my opinion, too prohibitive so have found Formula 1 Autocentres are doing a deal at the moment for £39.
They take a temperature reading from the A/C system, remove all the old refrigerant gas, oil and dye and then clean the whole system then remove any moisture from within.
Once the system has been thoroughly cleansed, will inject new oil, dye and refrigerant gas and take a temperature reading again to ensure that the Re-Gas has made a difference to the cold air temperature.
They are also doing a FREE 10 point spring check when booking online, worth considering, so intend to arrange this in the very near future.