For sure not orginal
Here are some more original M/52 skulls for comparison. Please do note the difference in detail, which you've done, as is quite important, among other things, too, of course. Your first hunch is usually the right answer, but no shame in a verification.
I find this marker is faked more often than most. If you're interested in purchasing a variant of this marker, I'd suggest studying original examples prior to doing so. There are some good ones, although the example you posting is clearly not one of them.
Good luck in your search, sir.