Photos include pieces before assembly, and assembly in-situ.
As I mentioned in the "thing" comments, I filed off just a little bit of each front lip/clip so I could snap them into place without having to disassemble my printer's gantry. I just hooked it over the back and pushed the clip into place. The friction with this feed setup is slightly less than my old holder (and will probably decrease over time as bearings are brand new and a bit stiff). I used to worry just a bit about my old holder hanging up at times.
My old holder was simply a printed extension to the stock holder on my printer (which has now been removed, of course).
I was able to use my existing filament guide without issues with this new holder - barely. ;)
(My Filament guide make: https://www.thingiverse.com/make:289316 ).