@mpw, i tried using a simple cardboard piece (2mm) available at the stationary shop for around 15/- rupees and cut them to size and placed my leather mat on top of it. The original Technics Rubber mat is now not being used. This helped me to get the VTA back to normal and i am enjoying what i hear. You can try this if the cardboard trick work for you, before you invest on the cork mat.
The cardboard helps to remove resonance by decoupling the aluminium platter which is hard metal.