The process involves complete strip of the action and annealing among many other steps along the way.

Mr Hurst is an excellent craftsman, another highly qualified American engraver for Brit scroll is Barry Lee Hands.
Google him for his contact information.

Ken and Barry are friends, and will be perfectly straight with you on the process, timeline, and price.
It's also probable that they would offer other references and/or craftsmen for you to consider.

Cheers
Tinker