Yes. It is no small task.
I also think it creates the most critical dilemma. The original artwork was not made with a computer. And no matter what tools you use, hand-drawn will never have the accuracy or the look of a computer. Now, you can use a the computer to reproduce those imperfections, but now you are looking at 3x-4x the time it takes to make the slick reproductions.
So most, if not nearly all reproduction decals just look wrong to me. I have no problem with over-restoration, but it is what it is.
It's usually pretty easy to pick out the restorations, as they're "too perfect". Some people like the ultra-realism, but mostly I'm with you. The
real masters know how to "wear down" a finish to match the original so you can't tell, which is important when doing a repair, for example.
I'm digging this thread. I've done a few vinyl decals, but never using them as a mask. The process seems pretty simple, it sounds like it's really just attention to detail to make it come out right.