My family used to own a brewery, where can I look to try to find our recipes?

My family used to own a brewery called Doerschuck Beer. They were originally from Germany, though I don't know if they had a brewery there (I think they did), and moved to Brooklyn and opened a(nother?) brewery pre-prohibition. Eventually the brewery had its plug pulled because of prohibition. The company was sold and started up again later, but I'm not sure what happened to it.

I asked some family members what they knew, but does anyone know of any resources I could use to try to find out more about their actual brewing process/recipes?