I went to the address Marszalkowska 53 and I even got lucky, because
some people who lived in that building let me in. So I went to see the
door of apartment 36. I attach photos - there are no plates anywhere.
It looks like the second of the photos you sent me is indeed a photo of
the same door, but the plate is gone now. The looks of the building,
I mean the outside facade is very different from what is shown on the
first of the photos you sent me, so it was probably made some place else.

I asked the people that let me in - they knew nothing of PESA. I asked
the guard again - he also did not know any PESA, but also said that he
wouldn't know, because there are many institutions there. He even said,
that the institutions must pay for plates (boards) hanging on walls so
some of them do not put plates to save money. But of course here Sienicki
clearly claims the plates are there, when in fact they aren't.