Focke en Melzer is (maybe was, haven't looked for a long time) a retailer of top quality tableware with branches in Amsterdam and The Hague, from the early 1900s or late 1800s to recent years. For many years they were the sole distributor for Lalique, but they basically carried all great brands.
The label therefore tells you who sold it, not who made it.
The decanters may be Danish, made by Holmegaard - but I'll need someone else to confirm this.
Welcome to the glass message board, nice that you found your way here.