Edge index with asciidoctor-pdf

Hi!
I want to produce a edge index with asciidoctor-pdf like in the example to the right..

I am able to insert images with  {section-title} name in the running header:

My images in theme subfolder:  "section-one.png", "section-to.png", "section-three.....

#------------------------------------------------------------------------------------------------
header:
 recto:
    right:
       content: "image:path_under_theme_directory/{section-title}.png[width=50]"
#------------------------------------------------------------------------------------------------




But how to "move" the images to the bleeding rand?



A different approach is to use a background image in full paper size, but that is not working with header/footers.
Thumb/edge index how to make with Word...

Someone with a good idea?
Volker

I don't have time to try this but it occurred to me that a workaround using the existing running header and footer functionality might be worthwhile exploring.