TVShowsonDVD.com announced on April 28th that "Perry Mason Season 3 - Volume 1" will be coming to DVD on August 19th. Here is a link to the news story:
Perry Mason DVD news: Announcement for Perry Mason - The Third Season, Volume 1 | TVShowsOnDVD.com
It sounds like it will be volume 1 of Season 3. I was hoping that they would do the whole season of shows in one set, but it does not appear to be that way.
I am looking forward to more Perry Mason in August.