Hmmm it's hard to believe that these have faced all kinds of weather for almost 100 or 90 years. Are there any historical photographs with these?
Couldn't these be newer lanterns made according to the original design?

Here are photos from the childhood of those masts:
https://lebork.fotopolska.eu/349535,foto.html?o=u106881
https://lebork.fotopolska.eu/349536,foto.html?o=u106881
After war:
https://lebork.fotopolska.eu/1015551,foto.html?o=u106881
https://lebork.fotopolska.eu/349541,foto.html?o=u106881
https://lebork.fotopolska.eu/240900,foto.html?o=u106881
https://lebork.fotopolska.eu/331255,foto.html?o=u106881
Shortly before current revitalisation there were added arms for modern fixtures:
https://www.lebork.pl/img2/w1140-h900/files/gallery/3332/4-003.jpg
No tricks, those masts are the real deal.
It's miraculous that they survived as weather wasn't the only affecting factor. During war the city was burning and was devastated in many ways. Even the buildings in close vicinity to the masts were destroyed.


Fortunately Lębork isn't the only case of a city with such masts, in the Legnica city which is located in the opposite part of contemporary Poland there are similar masts which survived all the way up to now:
https://legnica.fotopolska.eu/54942,foto.html?o=b15819
https://legnica.fotopolska.eu/141041,foto.html?o=b15819
https://legnica.fotopolska.eu/1216380,foto.html

Very cool lights!

Thanks for those links, trojmiejski! Those columns indeed must have been made of a top quality concrete.

Things made back there were generally made to last. For example many bridges made at that time are still in very good condition even if regularly used.