A few days ago, Mainspring Press published on their blog the 6th and final edition of Brian Rust's “Complete Jazz and Ragtime Records, 1897 – 1942”.
You can download it for free for personal use.
Response to the initial Personal Use Edition of the late Brian Rust’s JR-6 (1917-1934) has been so positive that we’re now making the complete work (1897-1942) available free of charge for the benefit of the collecting and research communities, in keeping with Brian’s wishes.
Link: Read the full article
You also find the license information there.
Please read it carefully before you download the file.