For a number of perforations in Dutch stamps, it is not sure it concerns real perfins. Your help is requested. You may also have somewhere still such a perforation, so that we can be more clearity about this.
If you have a perforation that is similar to the one above, I would like to hear from you, then we can investigate this further. Thanks in advance for your collaboration!

Nico van der Lee
e-mail: veilingmeester@perfinclub.nl