I'd give Mike a call at TSC machine in Doswell(right past kings dominion). He mostly does HK guns and is considered one of the best in that area(roller lock guns). I'd see if it is a service he would do.

I've had him engrave my sbr's and he has done some work on ar's for me(I didn't have the tools for the ar-10 upper). Everything he has done for me has been good. On my sig mpx he cut and threaded the barrel installing a 3lug, did the sbr engraving, and gave it a paint job. Came out great.