Here's a link to the Brooklyn Daily Eagle Almanac for 1908. I don't know if it will link to the correct page or not, but on page 429, the very last line on the page, a John Mulvaney is listed as an alderman for the 44th Local Improvement District. If the stories about Patrick's brother John being a Brooklyn alderman are correct, this is undoubtedly him.
Okay, that's a scary looking link. If it doesn't work, try this one: http://books.google.com/books?id=aBUrAAAAYAAJ, then click "read this book," and go to page 429. I haven't read any of the other pages in it, so if you browse and find anything interesting, let me know! There should also be a search box to the right where you can enter search terms.