Manual work for you. Here is the list of roses hybridized by Austin from helpmefind.com: Austin Roses. You need to find the registered name for each rose, which is listed in the Helpmefind.com information for each rose. That name starts with the prefix "AUS". For example, Abraham Darby's registered name is AUScot. Go to Google.com/patents and enter the registered name into the search box. If nothing is returned, then the rose is out of patent. If the rose is still under patent, the search will return a thumbnail of the patent and a link to the patent at the USPTO web site.

Decobug put a huge amount of work into this list. It is very handy. Scroll down to the 9th entry. Happy reading! :o)

Here is a link that might be useful: Austin Chronology