Very nice.
@newest dude on the forum engraved my 6610 lugs, I'm still looking for someone who is able to do the inside caseback sometime.
Just my humble opinion, but having used both the drag engraver and the laser and saltwater etching processes, I think the case back would be VERY difficult to do with the drag engraver.
The different fonts used and the fact that some of the writing is on an arc would make things very difficult to line up properly. It's doable, obviously, because Rolex did it at one time, but to do it one-off would be a challenge.
Since the inside case back is only visible to a watchmaker, who wouldn't be fooled once the case back was open anyway (a NH or ETA or even 31XX looks nothing like a 15XX movement), I'd think a "less than perfect" inside case back would be more than acceptable, and there's some decent templates to use in the saltwater engraving thread that would work.
Now for something like a Tudor case back, engraved on the outside, it would probably be worth the trouble to use the drag engraver.