UPDATE: Just changed the thermal paste to Arctic Silver 5, and the temperatures have dropped by almost 20 degrees on load and idle. The stock paste wasn't fully covering the GPU chip!! There was also visible damage to components on the PCB itself, solidified plastic droplets where it had melted itself was common! However it still works fine and after benchmarking using Unigine Heaven, I had temperatures fluctuating between 76-80 degrees immediately after application.
As the new thermal paste has a long curing time, the temperatures will only decrease thankfully!
Thanks all for the help.