Many years ago I used a famous "Gunsmith" touted on this & other forums and he wrecked two of my best guns. Eventually he straightened most (but not all) of the problems out but left me holding the bag for TWO SETS of custom Ivory grips which he absolutely destroyed beyond repair. Needless to say that was the LAST TIME I ever sent a gun out to a GS for work and that is why I now do all my own work (except grips, bluing, plating & barrels). I went through months of aggravation, many letters and phone calls but eventually got the guns back.
Three years ago after 20 or so years of shooting those guns in SASS matches, I sent them to COLT for a compete new Royal Bluing and new Case Coloring. After that the guns went to Dan Chesiak for new Ivory's. Those two Colts cost me a fortune because of one lousy Gunsmith but now look better than the day I bought them. These guns were personally hand delivered to both Colt & Dan and picked up the same way.
Bottom line is even when GS's are touted and applauded on forums does not mean that they will do the right thing, be upstanding businessmen, or respond to letters and phone calls. Some are just mean spirited, obnoxious, and think they are a gift to the gun world.
If he won't respond to any of your emails I would send a registered (return receipt requested) letter to him stating that you want the gun back in a timely fashion, and you would like to personally talk with him. If you still don't hear back, I would call the ATF and file a stolen gun report. If he has not completed the work by now I would tell him to simply return the gun along with your money. Some of these "famous GS's" are real pieces of work! They charge ridiculous amounts of money and make you wait an absurd amount time.
I hope to get your gun back and fair much better than I did.
Good luck and keep us posted.