Salvation Army Bb Tenor horn or baritone

[gbeuph]

I recently bought a Salvation Army Dixie Bb Tenor Horn or Baritone that was made by Boosey and Hawkes London. The SN is 423288. It appears to be built on pitch slightly lower than A440. I am interested in any info available about this instrument. When it was made, how B&H became involed, is this horn still being used by SA Bands???????