I'm familiar with the soft drink. I was just wondering if there were some additional bitters, e.g. Angostura, in this recipe at one point and that maybe that was why it is listed as a cocktail with alcohol.

30ml lime juice is too much imo

I'd also say that this is more usually a combination of a jonge jenever rather than an old and just a regular pilsener beer, whatever's on tap. The kopstoot is a bit old-fashioned I suppose, so I'm not entirely sure.
It's also costumary to have jenever, whether combined with a beer or not, straight from the fridge, poured right in front of the costumer to the very top of the tulip glass so there's a bit of a bulb at the top and the costumer has to bend their head towards the glass to drink the first sip so as not to spill. This part I'm sure of, since I was instructed to do so when I briefly worked in a bar in the Netherlands.

Two dashes of saline solution, is that correct? I usually just see a few drops in recipes.