If your sprockets are as bad as you say your chains are shot too. When the internal wear on the pins and bushings in the links gets too great the pitch becomes greater than the sprocket was designed for and wear increases. Chains eat sprockets sprockets dont eat chains.
There used to be a company that sold weld in sprocket inserts. I used to think of it as a patch up job it being better to weld on new rings. I think if the welded in bushings were thick enough it might increase the diameter of the sprocket enough to compensate for the incresed pitch in the chains. At least you might get some more life out of it.
Usually by the time this happens the rails are so thin the rock guards are wearing in the pads and the pins are taking out the roller flanges. Good to keep an eye out for a parts machine with good undercarriage