Sorry for the bump. These are all by the company known as Carl Th. Malling, later Malling Kontrol and now DEIF A/S. The siren in Greenland is also a Carl Th. Malling siren. I refer to them as Type A and Type B, as there are two different sirens with two different ports. I believe they're called some...

I have a map of the sirens in Denmark. Please don't edit it even if you spot one that I haven't spotted (it's a work in progress). Thanks for your understanding, here's the link:) https://www.google.com/maps/d/viewer?mid=1HIboKNWC_Y5S4IY8B7dHh3r_CFNd0und&ll=61.436613305380384%2C-18.2928904999999...