Salvation Army Tune Book

The Salvation Army Tunebook (2015) is available in two volumes (books).

Volume 1: 1-530 are for pieces which follow a set metre, allowing the different tunes to be used for the same lyrics
Volume 2: 531-958 are for pieces where the music is specifically written for the lyrics of the song

A US Review of the 2015 release can be found here.
A Canadian review of the 2015 release can be found here.

The Salvation Army Tunebook can be purchased from UK Trade: both Volume 1 and Volume 2.
There is also a mini size Solo Cornet part, softback only available here

For those interested in previous versions of the tune book, titles, indexes and comparison charts can be found at https://brasscrest.com/tunebook.html
There is also an online archival version of the original edition of the The Salvation Army Songbook (1911)