Re-Stucco or Recap

What is the best method to repair spider cracks on stucco, The house was built in 1965. I have also changed some windows that will require the missing stucco installed, the main concern is that how good would stucco bond to the old painted stucco if we left it on, and would the new patches be visible once the job is done, is it necessary to remove the old stucco i am getting conflicting responses