Nice twintub, but so far it doesn't ring a bell. I will have to get a look at my older brochures, but that has to be done with a face mask because they are beginning to deteriorate. And I will have a look at some copies of Dutch ads. I have no high hopes though, there were so many Dutch manufacturers, it's hard to get a full picture of what was made here.
BTW, are you sure it's Dutch or German?