smiths westminster chiming 3 hole mantel clock?

I have been given the above clock...I am very fond of chiming clocks and would really love to get it working again. I fear it has been over wound as when the key is put into the key holes they all feel tight and fully wound up.the chimes work and sound if you manually move the big hand.Does any one have any advice ...is there any hope of getting this clock ticking again...Thanks