Question about black widow Lugers and wooden grip guns

[carl1000]

From what I have read and watched videos of, isn't it true that you can take any 40-42 BYF Luger and turn it into a black widow just by changing out the grips and the magazine? So, when someone is selling a black widow Luger, is not impossible to tell for sure that it was that way from the factory?

If it is impossible, I guess I'm confused by the collectibility of them other than they look cool being all black. I know the grips and the magazines are more rare. Just curious if I correct in thinking this.