You sure have put me to work!
Checked another dozen:
- one had no HKDNP, nor a year.
- all the others did, of which one was 2004, one 2006, the rest all 2007/8.
I also found three 2017s, all without HKDNP.
I'm going to draw the line here, to reach all the other houses I would have to stand on a stool and perform acrobatics. That's not going to happen.
Johan