Scipio
I can tell you that through the years there were many changes to the route, especially toward the end of it's time. For instance I show the route starting in Benacre Street, but after that street disappeared it used Wrentham Street and Gooch Street North to get from Bristol Street to Vaughton Street (see photo) and if you look at the photo of the 19 bus turning left into Bordesley High Street when it should be turning right. I suppose they were using Heath Mill Lane by then to get to Lawley Street.