Hey Susan,
I'm retired from the FDNY, working on a website which will include the history of the job, and I'd love to talk to you about your great-grandfather Edward Croker. I want to memorialize all the men we've lost over the years, and document as much of the history of the job and the men who've served, and I think having family members contribute memories or comments would be a very nice addition to it. If you're interested, you can contact me here through ancestry, or try my cell at 845-590-7992. The website won't be up for another six months or so, lots of work and research to do for it, but your input would be welcome.
My best,
Tom McLoughlin