When I look down inside the battery connection on mine, I see what could be
threads - but looks more like machining marks actually.
The really big difference is on the outside. I see yours machined smooth, where the first shoulder above the band where the button is on mine is
threaded. So yes, there is definitely a difference.
That threaded part is what the atty screws on to.
I have every reason to believe that this one here is the real deal - but anything is possible.
Do you have access to a store in your area that sells things like atomizers? There must be something that would fit it.