Can I repair a stone step?
Absolutely you can repair it! A photo would be helpful to give us a idea what is needed, etching and adding a new layer or maybe a thin stone veneer to help it look original. I have etch granite steps that were worn over 100 years a thin layer of mortar holding a 1/4 inch granite slab on top of the steps was approved and later awarded for a restoration project on a Vicky, ( one of about a dozen things that were mentioned in the award) but this was decades ago. The same process will still work.