My own particular instance was to get as much as I could about an ancestor who was a prominent bandmaster at Regent Hall so I wrote to the SA Heritage Centre at 117 Judd St. London in 1995 and they sent me a whole wealth of photocopies of 'The Bandsman' and 'The Songster' dating back to June 1910 which carried articles about him which,at times,included details of the death of his wife and subsequent remarriage and names of his children which I just would not have obtained at that time from any other source.
I congratulate you that you were able to get this information. When I have made enquiries of Salvation Army centres in a certain locality I was advised to contact my local Salvation Army and in any case they would not release the information as it was deemed to be classified. I found my information through looking at Kelly's Directory, but it was a lot more general that what you were seeking.