You'll have to draw the markings on "Periscope_Mask_1024_SH5" in ..\Ubisoft\data\Menu\Skins\German\Gui\Layout
Guess you could scale Hitman's graphics to fit the the new mask, and then draw the marks on a new layer (kinda like papertracing, it's how I did the stock markings on mine). Once you have the marks drawn, remove the layer with Hitman's graphics, put the layer with the marks underneath the new mask, and merge those 2 layers.
I can give it a shot if you'd like, but shouldn't be too difficult.