I was intrigued by the pictures of the holes in the weathervane, and it reminded me of something from my youth. A friend lives in one of the houses on Skerries Street (the ones behind the railings in the first picture). When I was a child visiting their house, I can remember they had a small hole in an upstairs window )blocked off), that they said had been caused Christmas Day one year (I'm guessing 1950's) by someome firing an air-rifle through it.I wonder if that would be connected?
I saw your great pictures of the weather vane removal yesterday.... I think maybe the holes were caused by lightening strikes.
As you can see the conductor in one of the photos it is likely the electicity striking the weather vane could have caused localised super heating and thus the production of the holes......