At the official (LFS) "Obtaining and Installing DirectX 9" page, you wrote that "You probably came to this page looking for a download link to the proper DirectX 9 files. However Microsoft doesn't seem to provide them anymore, so there is no download link anymore...".
Closely following another DirectX9 game (Orbiter) I have a couple links that we use to share among users:
DirectX End-User Runtimes (June 2010)
Version: 9.29.1974
File Name: directx_Jun2010_redist.exe
Date Published: 4/18/2011
https://www.microsoft.com/en-us/download/details.aspx?id=8109
and
DirectX End-User Runtime Web Installer
Version: 9.29.1974
File Name: dxwebsetup.exe
Date Published: 4/18/2011
https://www.microsoft.com/en-US/download/details.aspx?id=35
Maybe they are the same runtimes you included in LFS?
EDIT: text on that page has changed, according to Scawen's post
Closely following another DirectX9 game (Orbiter) I have a couple links that we use to share among users:
DirectX End-User Runtimes (June 2010)
Version: 9.29.1974
File Name: directx_Jun2010_redist.exe
Date Published: 4/18/2011
https://www.microsoft.com/en-us/download/details.aspx?id=8109
and
DirectX End-User Runtime Web Installer
Version: 9.29.1974
File Name: dxwebsetup.exe
Date Published: 4/18/2011
https://www.microsoft.com/en-US/download/details.aspx?id=35
Maybe they are the same runtimes you included in LFS?