Basically IOI just removed the markings and made the Silverballer black with white grips.
And I see now on the Silverballer there are less writings but I think it is like this because of the technology back then. Remember the Silveballer in Contracts? It was all blurry.
When looking at the marks on the gun, I'm looking at the wallpapers and not ingame, because the wallpapers represent how it should look in reality. Besides from Absolution and HITMAN 6 because they are more graphically advance.
Here is an example how the position of the markings change during the games
Another example. In Hitman 6 the position and size of the markings and logo are different. In the wallpapers they appear to be small, while ingame the size is a bit bigger. I decided to go with the ingame size because it looks more right to me.
PS: Damn I need to download Blood Money now. Nostalgia is hitting me